One-Pot Process for Hydrodeoxygenation of Lignin to Alkanes Using Ru-Based Bimetallic and Bifunctional Catalysts Supported on Zeolite Y

Article abstract of DOI:10.1002/cssc.201700160

The synthesis of high-efficiency and low-cost catalysts for hydrodeoxygenation (HDO) of waste lignin to advanced biofuels is crucial for enhancing current biorefinery processes. Inexpensive transition metals, including Fe, Ni, Cu, and Zn, were severally co-loaded with Ru on HY zeolite to form bimetallic and bifunctional catalysts. These catalysts were subsequently tested for HDO conversion of softwood lignin and several lignin model compounds. Results indicated that the inexpensive earth-abundant metals could modulate the hydrogenolysis activity of Ru and decrease the yield of low-molecular-weight gaseous products. Among these catalysts, Ru-Cu/HY showed the best HDO performance, affording the highest selectivity to hydrocarbon products. The improved catalytic performance of Ru-Cu/HY was probably a result of the following three factors: (1) high total and strong acid sites, (2) good dispersion of metal species and limited segregation, and (3) high adsorption capacity for polar fractions, including hydroxyl groups and ether bonds. Moreover, all bifunctional catalysts proved to be superior over the combination catalysts of Ru/Al₂O₃ and HY zeolite.

Full text of DOI:10.1002/cssc.201700160

Accepted Article
Title: One-Pot Process for Hydrodeoxygenation of Lignin to Alkanes
Using Ru-based Bimetallic and Bifunctional Catalysts Supported
on Zeolite Y
Authors: Hongliang Wang, Hao Ruan, Maoqi Feng, Yuling Qin,
Heather M Job, Langli Luo, Chongmin Wang, Mark H
Engelhard, Erik Kuhn, Xiaowen Chen, Melvin P Tucker, and
Bin Yang
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: ChemSusChem 10.1002/cssc.201700160
Link to VoR: http://dx.doi.org/10.1002/cssc.201700160
A Journal of
www.chemsuschem.org

10.1002/cssc.201700160
ChemSusChem
FULL PAPER
One-Pot Process for Hydrodeoxygenation of Lignin to Alkanes
Using Ru-based Bimetallic and Bifunctional Catalysts Supported
on Zeolite Y
Hongliang Wang,[a]Hao Ruan,[a]Maoqi Feng,[b] Yuling Qin,[a]Heather Job,[c]Langli Luo,[d]Chongmin
Wang,[d]Mark H. Engelhard,[d] Erik Kuhn,[e]Xiaowen Chen,[e]Melvin P. Tucker,[e]and Bin Yang*[a]
The synthesis of high-efficiency and low-cost catalysts for
hydrodeoxygenation (HDO) of waste lignin into advanced biofuels is
crucial for enhancing current biorefinery processes. Inexpensive
transition metals, including Fe, Ni, Cu, Zn, were severally co-loaded
with Ru on HY zeolite to form bimetallic and bifunctional catalysts.
These catalysts were subsequently tested for HDO conversion of
softwood lignin and several lignin model compounds. Results
indicated that the inexpensive earth abundant metals could modulate
the hydrogenolysis activity of Ru and decrease the yield of low
molecular weight gaseous products. Among these catalysts, Ru-
Cu/HY showed the best HDO performance, giving the highest
selectivity to hydrocarbon products. The improved catalytic
performance of Ru-Cu/HY was probably due to the following three
factors: (1) high total and strong acid sites, (2) good dispersion of
metal species and limited segregation, (3) high adsorption capacity
for polar fractions, including hydroxyl groups and ether bonds.
Moreover, all the bifunctional catalysts were proven to be superior
over the combination catalysts of Ru/Al2O3 and HY zeolite.
chemical structure, lignin is recalcitrant to conversion, especially
selective, under either thermal, catalytic, or biological conditions.
The difficulty in lignin valorization thus significantly reduces
biorefinery product slates in commercial production. As a matter
of fact, most of the current biorefinery processes, such as
bioethanol production, only focus on the utilization of cellulose
and hemicellulose. The large amount of residual lignin is treated
as waste or as low value-added solid fuel.[2] Therefore, better
utilization of lignin for the production of value-added chemicals or
advanced biofuels will contribute to the economics of modern
lignocellulosic biorefineries. Increased attention has been
focused in recent years on lignin valorization, with various
processes attempted.[3] However, the selective conversion of
lignin to well-defined products is still a nascent endeavor.[4]
Hydrodeoxygenation (HDO) conversion of lignin, in which
lignin is depolymerized and deoxygenated using hydrogen over
catalysts, is regarded as one of the most promising ways to
transform lignin into value-added aromatics or fuel range
hydrocarbons.[5] However, to make this process industrially viable,
several challenges, especially the development of highly effective
catalysts with low cost, should be addressed. Sulfided CoMo and
NiMo-based catalysts that are traditionally developed for removal
of sulfur and nitrogen in the industrial hydrotreating of
petrochemical feedstocks were introduced into lignin HDO
conversion.[1b] However, these catalysts showed several
intractable problems, such as sulfur contamination of the products
(the catalyst needs H2S for stabilility), rapid deactivation of the
catalysts during reaction because of sulfur deprivation, and easy
catalyst poisoning by the water generated in the reaction.[6] Noble
metals as catalysts, typically including Pt,[7] Pd,[8]Re,[9]Rh,[10] or
Ru[11] loaded on various supports, have also been used, showing
Introduction
Lignin is one of the three major components in lignocellulosic
biomass, and it is also the only large-volume renewable resource
for aromatic compounds. Lignin has a higher C/O ratio and energy
density than the other two biomass components, namely cellulose
and
hemicellulose
(carbohydrates).[1]
Compared
with
carbohydrates, lignin is very heterogeneous, consisting mainly of
three different phenylpropanoid units linked by various C-O-C and
C-C bonds. Given its three-dimensional, highly branched
high catalytic activities
towards hydrogenolysis and
hydrogenation reactions.[12] Among these noble metals, Ru is the
least expensive and exhibits superior HDO performance in an
aqueous phase.[11c]Arjan Kloekhorst et al. recently performed a
catalyst screening study on the catalytic hydrotreatment of Alcell
lignin, and found that the best results for conversion in high yields
of lignin to bio-oil were obtained from supported Ru catalysts.[11d]
Ru-based bimetallic catalysts or bifunctional catalysts were
also prepared with the aim to increase and fine-tune the HDO
catalytic activity towards lignin conversion, as well as to further
reduce catalyst costs. In this respect, unsupported bimetallic RuNi
nanoparticles were successfully synthesized by Yan’s group, and
were tested for the conversion of lignin model compounds. The
results suggest that the catalytic activity of Ru0.15Ni0.85
nanoparticles was found to be superior when compared to single-
component catalysts.[13]Bimetallic catalysts, which usually show
different electronic and chemical properties from their parent
metals, have gained considerable academic and commercial
[a]
Dr. H Wang, H Ruan, Dr. Y Qin and Prof. B Yang
Department of Biological Systems Engineering
Washington State University
Richland, WA 99354, USA
E-mail: binyang@tricity.wsu.edu
[b]
Dr. M Feng
Chemistry & Chemical Engineering Division
Southwest Research Institute
San Antonio, TX 78238, USA
HM Jo
Pacific Northwest National Laboratory
902 Battelle Blvd, Richland, WA 99354, USA
Dr. L Luo, Dr. C Wang, MH Engelhard
Environmental Molecular Sciences Laboratory
3335 Q Ave, Richland, WA, 99354, USA
E Kuhn, Dr. X Wen, Dr. MP Tucker
National Bioenergy Center, National Renewable Energy Laboratory
15013 Denver West Parkway, Golden, CO., 80401, USA
[c]
[d]
[e]
Supporting information for this article is given via a link at the end of
the document.((Please delete this text if not appropriate))
This article is protected by copyright. All rights reserved.

10.1002/cssc.201700160
ChemSusChem
FULL PAPER
interest since the 1960s, due to their enhanced performances of
selectivity, activity, and stability in various reactions.[14] The
electronic environment of the metals in bimetallic catalysts can be
changed by the formation of heteroatom bonds, which can lead to
modifications of the electronic structure of metals through ligand-
binding effects.[15] Also, the formation of heterogeneous
metal−metal bonds in bimetallic catalysts can cause changes in
orbital overlap, resulting in the strain effects that can alter the
geometry of the bimetallic structures.[16] Both the electronic
structure and the surface geometry of a catalytic material greatly
affect its catalytic performance. By combining suitable metals in
bimetallic catalysts, it is possible to synthesize the desired
catalyst with unique catalytic activities for a specific reaction.
Despite the great potential of bimetallic catalysts, the design and
usage of them for lignin conversion are still in their infancy.
Acidic zeolites, well-established heterogeneous catalysts,
have been successfully used in commercial industries including
catalytic cracking, isomerization, and alkylation reactions.[17]
Zeolites with suitable Si/Al ratios (acidity) and pore structures
were shown to be effective heterogeneous catalysts in lignin
deconstruction.[11h,18] Zeolites are also widely used as support
materials for transition and/or noble metals, constituting most
bifunctional catalysts. The electronic interactions of the supported
metal particles with the highly charged environment of zeolites
makes these metal particles stable, and results in superior
catalytic activity compared to conventional aluminum or silicon
oxide supported catalysts.[19] Bifunctional ruthenium catalysts
supported on various zeolites have been synthesized by several
groups for the HDO conversion of lignin model compounds[11h] or
lignin-derived bio-oil.[11e] Literature reports indicate that these
catalysts are highly effective at removing oxygen-containing
groups and saturating the aromatic rings. Very recently, we have
reported that the combination of a Ru-based catalyst with an
acidiczeolite formed a reliable catalytic system capable of
Ni, Cu, Zn) were prepared and tested for lignin model compounds
and softwood lignin HDO conversion in this study. Both Ru and
inexpensive metal (M) loading were 2.5 wt% in all of the
investigated bimetallic catalysts, while the Ru loading was 5 wt%
when it was loaded alone.
Initially, the prepared catalysts were tested in the HDO of
guaiacol, a typical lignin model compound, at 250°C with 4 MPa
H2 for 2 h in an aqueous phase. Guaiacol was used as a model
compound since it has three characteristic C-O bonds that are
commonly encountered in lignin, namely Cmethyl-OAr, Caryl-OMe
and Caryl-OH, with their respective bond dissociation enthalpies
(BDE) of 262-276, 409-421, and 466 kJ mol−1.[21]
Although guaiacol conversion was more than 90 wt% over all
of the investigated catalysts, Table 1 shows that relatively higher
lignin conversions had been obtained over bimetallic catalysts
than that over Ru/HY, especially, when Ru-Cu/HY or Ru-Zn/HY
were used, where almost all of the guaiacol was converted. This
result indicates that the bimetallic catalysts possess higher HDO
activities than Ru/HY. Table 1 shows 8 kinds of products that were
obtained from HDO of guaiacol over the investigated catalysts.
Catechol, phenol, and benzene were usually observed as
products in guaiacol HDO reaction.[21] However, none of these
compounds were detected in our research, indicating the high
hydrogenation activity of the prepared catalysts, which can
achieve full aromatic ring saturation reaction. Products of p1~p4
contain
oxygen
functional
groups,
among
which
cyclohexanone(p1) and cyclohexanol (p2) are the common
intermediates that can be typically found in guaiacol HDO
reactions. An non-negligible amount of p3 and p4, which were
probably isomerized from p1 and p2, respectively, were formed
over all of the investigated catalysts, with slightly higher
selectivities over bimetallic catalysts than that over Ru/HY.
Products of p5~p7 are hydrocarbons. Cyclohexane (p5) was
derived by the complete HDO of guaiacol, while p6 and p7 were
derived from dimerization and ring-opening reactions,
respectively. Table 1 shows that the investigated bimetallic
catalysts can generate higher yields of cyclohexane than that
found with the monometallic catalyst. The highest yield of
cyclohexane (~45%) was obtained by Ru-Cu/HY catalysis. The
total yield of hydrocarbon products was approximately 62% over
Ru-Cu/HY catalyst, indicating the higher HDO catalytic activity of
this bimetallic catalyst.
selectively
converting
lignin
to
jet
fuel
range
hydrocarbons.[3b]Encouraged by these papers, we were
interested in using earth-abundant metals, including Fe, Ni, Cu,
Zn, to partially replace the noble metal Ru, resulting in the
synthesis of bimetallic catalysts that were supported on HY zeolite
for lignin HDO conversion. HY zeolite was chosen in our
currentstudy because it possesses high concentrations of active
acid sites that were crucial for the lignin hydrolysis and
hydrodeoxygenation activities.
Different properties of bimetallic catalysts from those of the
corresponding
monometallic
catalysts,
including
the
enhancement of hydrogenation activities, have been observed by
previous researchers.[14] According to their results, the
enhancements of hydrogenation activities on the bimetallic
surfaces have been correlated to the modification of the electronic
properties due to the formation of subsurface bimetallic
structures.[22]To facilitate the hydrogenation reaction, one
hypothesis is that an effective catalyst should bond relatively
weakly to the reactants to keep the carbon–carbon and carbon–
hydrogen bonds intact.[14] Hammer and Nørskov have shown that
the binding strength of molecules on transition metals is
dependent on the electronic structure of the surface, by using the
surface d-band center with respect to the Fermi level to describe
the surface electronic property.[23] Chen et al. have summarized
Results and Discussion
Hydrodeoxygenation of guaiacol over Ru-based bifunctional
catalysts supported on HY zeolite
Our previous studies indicated that the combination of noble
metal catalyst (Ru/Al2O3) in the presence of acidic zeolite (HY)
had
a high hydrodeoxygenation (HDO) activity on lignin
conversion.[3b] A catalytic process which could produce jet fuel-
range hydrocarbons from lignin was demonstrated. In order to
integrate the noble metal catalyst and the acidic zeolite in one
catalyst, as well as to increase the efficiency of noble metal
utilization, bifunctional catalysts with bimetals Ru-M/HY (M= Fe,
This article is protected by copyright. All rights reserved.

10.1002/cssc.201700160
ChemSusChem
FULL PAPER
experimental and theoretical studies that identify a nearly linear
relationship between the binding energies and the surface d-band
center for many adsorbates on a wide range of bimetallic
Table 1.Hydrodeoxygenation of guaiacol over Ru/HY and Ru-M/HY (M=Fe, Ni, Cu, Zn) catalysts.[a]
Product distribution (wt. %)
Hydrocarbon
Yield (p5~p7)
30.0
Conversion
(wt%)
91
Catalyst
1
2
3
4
5
6
7
8.2
10.9
10.8
8.1
8
Ru/HY
27.5
22.8
21.0
13.1
17.2
18.1
11.0
11.6
8.1
3.5
6.1
5.1
3.9
5.8
7.9
8.8
11.3
8.1
10.2
18.5
29.9
28.4
44.8
32.6
6.3
3.2
3.4
9.5
8.2
10.0
7.3
8.4
4.4
6.1
Ru-Fe/HY
Ru-Ni/HY
Ru-Cu/HY
Ru-Zn/HY
96
95
>99
>99
42.2
40.5
62.4
51.7
9.0
10.9
[a] Reaction conditions: water, 30 mL; catalyst, 100 mg; guaiacol, 100 mg; hydrogen pressure, 4 MPa; reaction temperature, 250oC; reaction time 2 h.
surfaces.[24] In the hydrogenation reaction, the shifts in the surface
As mentioned above, no aromatic products were detected in
d-band center on the bimetallic surfaces affect the binding energy
the process, indicating all the synthesized catalysts have high
of both atomic and molecular adsorbates on the catalysts. Some
hydrogenation activity towards completely saturating the aromatic
of the bimetallic surfaces formed from 3d transition metals
rings. Based on the obtained products, we proposed a reaction
(including Fe, Ni, Cu, Zn) and noble metals (such as Ru, Pt, Pd)
pathway of guaiacol hydrodeoxygenation conversion over acidic
with shifts of the d-band center closer to the Fermi level have been
zeolite HY supported Ru and bimetallic Ru-M catalysts, and this
demonstrated to be more weakly bonded to reactants than the
is depicted in Scheme 1.
parent metals (Ru, Pt, Pd).[24] Thus, compared with Ru/HY, the
It has been reported that the aromatic ring of guaiacol can be
enhanced HDO activity of the prepared bimetallic catalysts in
fully hydrogenated over acid-catalyst supported precious metal
thisstudy could be attributed to the formation of the bimetallic
catalysts when heated from room temperature to ~108°C.[26] Thus,
structures with modified electronic properties.
the first step of guaiacol HDO reaction in our studies probably
The HDO conversion of lignin and lignin model compounds
involved the addition of 3 moles of hydrogen to the aromatic ring
include various kinds of reactions, such as hydrogenation,
to generate a product of 2-methoxycyclohexanol. After that, 2-
hydrogenolysis, dehydration, dimerization and isomerization
methoxycyclohexanol could be converted to cyclohexan-1,2-diol
reactions. Ru has been shown to be the most active catalyst for
via the hydrogenolysis of Cmethyl-O bond. The produced
hydrogenolysis; however, it is well known to have high rates of C-
cyclohexan-1,2-diol can undergo further dehydration reactions to
C bond cleavage[25],which leads to excessive production of
form cyclohex-1-en-1-ol which could easily isomerize to yield
lowmolecular products (C1~C4 gaseous products, Table 1 p8).
cyclohexanone. Cyclohexanone was an important intermediate in
The selectivities of gas products were lower over the investigated
the process, the selectivity of which was higher than other
bimetallic catalysts, indicating 3d transition metals (M) in catalysts
oxygen-containing intermediates. Hydrogenation of the aromatic
of Ru-M/HY (M=Ni, Fe, Cu, Zn) could modulate the
ring in guaiacol (with 2-methoxycyclohexanol product), followed
hydrogenolysis activity of Ru and improve the HDO behavior,
by a demethoxylation and/or dehydroxylation pathway (with
which then results in higher selectivity to high carbon number
cyclohexanone/cyclohexanol and cyclohexane products) have
hydrocarbon products (C>5). Moreover, it is noteworthy that when
been proposed in the HDO of guaiacol on Rh-based
Cu was used to combine with Ru, the lowest yield of gas products
catalysts.[27]To verify this,the guaiacol HDO reaction time was
was achieved. Meanwhile, high selectivities to p5 (cyclohexane)
reduced to
1
h,
and both 2-methoxycyclohexanol and
and p6 (dimers) were obtained, suggesting Cu in Ru-Cu/HY could
obviously decrease the hydrogenolysis activity of Ru while
maintain high hydrodeoxygenation activity.
cyclohexan-1,2-diol were detected, indicatingthe pathway for
cyclohexanone formation in our study is in agreement with the
literature. However, this result is different from other reports which
have shown that cyclohexanone was obtained directly from
phenol during guaiacol HDO reactions when Cu, Fe or Pt-Fe
based catalysts were used.[21] Cyclohexanone was not stable in
our reaction. Catalysis with acidic HY zeolite or oxides could
isomerize cyclohexanone to form cyclopentanecarbaldehyde (p3),
or hydrogenated to produce cyclohexanol (p2). Cyclohexanol can
undergo further dehydration reactions over acidic HY zeolite or
oxides to generate cyclohexene which could be facilely
hydrogenated to the main product of cyclohexane. It is worth
noting
that
though
a
significant
amount
of
cyclopentanecarbaldehyde (p3) and cyclopentylmethanol (p4)
were detected in the reaction, the HDO products from them, such
as cyclopentane and its derivatives, were not found. This may be
Scheme 1. Proposed reaction pathway of guaiacol with bifunctional
catalysts.
This article is protected by copyright. All rights reserved.

10.1002/cssc.201700160
ChemSusChem
FULL PAPER
due to the instability of these products which were prone to go
over-hydrogenolysis reaction toform low molecular weight
products. Some dimers and ring-openproducts were also
detected in the products, indicating that the dimerization and ring-
open reactions occurred during HDO.
Table 2.Hydrodeoxygenation of lignin model compounds over Ru-Cu/HY catalyst.[a]
Product selectivity
Substrate
Conversion
1
2
3
4
5
83
8.5
81.6
5.1
0.8
3.9
6.4
>99
>99
56.1
23.6
7.5
7.8
2.3
5.7
1.8
85.1
0.9
[a] Reaction conditions: water, 30 mL; catalyst, 100 mg; Lignin model compound, 100 mg; hydrogen pressure, 4 MPa; reaction temperature, 250oC; reaction
time 2 h.
Soft wood lignin isolated from flowthrough reactor was used
Hydrodeoxygenation of other lignin model compounds over
to test the catalytic HDO activity of the prepared catalysts. In a
typical reaction, 100 mg pine wood lignin, 100 mg bifunctional
catalyst were dispersed in 30 ml DI water and reacted at 250oC
Ru based bifunctional catalysts supported on HY zeolite
In order to further evaluate the HDO reactivity of the prepared
under 4 MPa hydrogen for 4 h. After reaction, the products of the
reaction were extracted by using 30 mL ethyl acetate and
analyzed by using GC and GC-MS. The HDO results are depicted
in Figure 1.
bimetallic catalysts, Ru-Cu/HY was selected as a representative
catalyst for the HDO of additional lignin model compounds,
including diphenyl ether (DPE), (benzyloxy)benzene (BB) and
benzofuran (BF).
DPE is usually chosen as the model compound of 4–O–5
linkages in lignin for investigating the aryl-O-aryl bond cleavage
chemistry.[28] The 4–O–5 bond is reported as the strongest ether
bond in lignin with the bond dissociation energy (BDE) as high
as314 kJ mol-1.[29] The cleavage of an aryl-O-aryl bond usually
requires harsh conditions. Without catalysts, DPE has been
reported to be unreactive in water at temperatures below
500°C.[30]
In
this
study,DPE
conversion
was
approximately83%after reaction at 250°C for 2 h, suggesting the
high HDO reactivity of Ru-Cu/HY catalyst. BB and BF are used to
represent the α–O–4 and β-5 structures in lignin, respectively.
The HDO results of the model substrates indicate that both of
them could be converted at high yields. Cyclohexane was found
to be the main product when DPE and BB were used as reactants.
However, the prevailing HDO product from BF was found to be
octahydrobenzofuran, with the intramolecular ether bond
Figure 1. Hydrodeoxygenation of soft wood lignin over various bimetal-HY
catalysts. Reaction conditions: water, 30 mL; bifunctional catalyst, 100 mg, [or
5 wt.% Ru/Al2O3 (300 mg) + HY (300 mg), optimized loarding]; lignin, 100 mg;
hydrogen pressure, 4 MPa; reaction temperature, 250oC; reaction time 4 h.
remaining intact.
A
small amount of dimer products
(dicyclohexylmethane) was detected in the HDO products of BB
and BF, suggesting the dimerization reactions can occur after the
cleavage of ether bonds during the reaction.Results indicated that
much less isomerization prouducts were generated from these
model compounds than those from guaiacol, probably because
the phenolic hydroxyl group and methoxyl group can increase the
electron density of the aromatic ring and thus increase the
isomerization reactivity of guaiacol.
Hydrodeoxygenation of softwood lignin over Ru based
bifunctional catalysts supported on HY zeolite
This article is protected by copyright. All rights reserved.

10.1002/cssc.201700160
ChemSusChem
FULL PAPER
were carried out to reveal the physical and chemical properties of
these catalysts. Table 3 lists the surface area values, pore
volumes, and average pore diameters of HY zeolite and the
synthesized bifunctional catalysts. The BET surface area of HY is
724 m2/g, while the BET surface area of all the five supported
catalysts is approximately 600 m2/g. The impregnation of Ru, or
bimetals into HY zeolite, caused some reduction in pore volume
and pore diameter. This phenomenon is common in supported
catalysts. In spite of the decrease of the BET surface area and
the closure of some of pores by active metals, all of these
materials still have sufficiently high surface area values for
catalytic purposes.
Typical nitrogen adsorption/desorption isotherms of the
prepared catalysts are shown in Figure S1. Isotherms showing
similar type IV curves and porosities were obtained for all the
synthesized catalysts, indicating that pore structures of these
materials were mesoporous with narrow pore size distributions.
Results obtained from the BET test and nitrogen
adsorption/desorption tests suggest that all the prepared
supported catalysts have relative high surface area values and
keep the typical mesoporous structure of HY zeolites. The
physical porosity of these catalysts are similar, indicating the
differences in their catalytic activity are not from changes in
physical properties of HY zeolite but from other influences.
Figure 2.GC-MS chromatogram of lignin conversion over Ru-Cu/HY catalysis.
The conversion of softwood lignin and the yield of detectable
products were very low when there was no catalyst in the control
reaction. Adding the prepared catalysts, the lignin conversion and
HDO product yields increased significantly. Lignin conversion was
found in the same level over all five of the catalysts. Hydrocarbon
selectivities were a little higher over Ru-Cu/HY catalysis than over
the others, possibly because the activation energy for hydrogen
bulk diffusion over Cu was much smaller than that over other
metals.[32]
The detected product slate for the catalysts tested was similar,
with cyclohexane derived alkanesin jet-fuel or diesel range as the
majority of the products, as depicted in Figure 2. Small fractions
of oxy-compounds and ring-opening products were also detected.
The total yields of the detected hydrocarbon products were
approximately 26 wt% to 32 wt%, which were higher than that
found over the combination catalysis of Ru/Al2O3 and HY zeolite
(22 wt%), indicating the integration of metals with acidic zeolite
can increase the catalytic selectivity of hydrocarbons from lignin
HDO. The superior catalytic activity of Ru-M/HY over that of
combination catalyst could be attributed to the so-called intimacy
criterion.[31] In metal-acid bifunctional catalysts, the proximity of
metal sites to acid sites is crucial for their catalytic capability.[32]
Large distances between metal and acid sites always lead to low
diffusivity of reaction intermediates, giving rise to gas and coke
products via secondary reactions.[31-33] Thus, for the two functional
sites, the closer the better. Obviously, in bifunctional catalysts of
Ru-M/HY, the distances between metal and acid sites are much
smaller than that in the combination catalysts of Ru/Al2O3 with HY
zeolite.
Table 3. Physical properties of HY zeolite and the synthesized catalysts.
Catalyst
BET surface area
(m2/g)
Pore volume
(cm3/g)
Average pore
diameter (nm)
HY
724
0.40
0.37
0.36
0.34
0.37
0.38
2.48
2.46
2.44
2.29
2.51
2.46
Ru/HY
608.52
598.54
591.13
587.92
604.53
Ru-Fe/HY
Ru-Ni/HY
Ru-Cu/HY
Ru-Zn/HY
Table 4 Acid properties of the prepared catalysts.
Catalyst
Ru/HY Ru-Zn/HY Ru-Cu/HY Ru-Ni/HY
Ru-Fe/HY
0.130
Total mL
(NH3/g cat.)
0.089
0.099
0.123
0.122
The conversion of lignin and the selectivity of products might
strongly depend on the acid properties of the catalyst.[34] Thus,
NH3-TPD measurements were carried out to determine the
relationship between the activity of the catalyst and the number of
acid sites. Table 4 lists the uptakes of NH3 per gram of catalysts,
which can reflect the number of acid sites in these catalysts. The
acidity of the prepared bifunctional catalysts is mainly derived
from the acidic HY zeolite support. The impregnation of different
metals in the support may result in different acid properties in the
catalysts. As shown in Table 4 there are some slight differences
in the number of acid sites in these catalysts. If we rank them by
NH3 uptake we have two sets. Ru/HY and Ru-Zn/HY showed
lower uptake compared to Ru-Cu/HY, Ru-Ni/HY, and Ru-Fe/HY,
indicating the total number of acid sites in the last three catalysts
Structural characterization of Ru-based bifunctional
catalysts supported on HY zeolite
In order to make clear why bimetallic catalysts of Ru-M/HY
(M= Fe, Ni, Cu, Zn), especially Ru-Cu/HY, exhibited better
catalytic performance than Ru/HY in the HDO conversion of lignin
models and softwood lignin, some essential characterizations
This article is protected by copyright. All rights reserved.

10.1002/cssc.201700160
ChemSusChem
FULL PAPER
are slightly higher than that inRu/HY and Ru-Zn/HY. The higher
catalytic activity of Ru-Cu/HYin lignin HDO conversion may have
some relationship with its higher number of acid sites. Figure 3
shows the NH3-TPD profiles of the prepared catalysts. The
profiles of NH3 desorbed from the catalysts can be representative
of the acid strength distribution on the catalysts. NH3 adsorbed on
stronger acid sites could be desorbed at higher temperatures than
that on weaker acid sites. Deconvolution of the traces shows
essentially two peaks: one at approximately 220°C and the other
at approximately 300°C. Desorption of later peaks (higher
temperature) indicate stronger acid sites on the catalyst. The ratio
between the second to the first peak was found to be larger in the
Ru-Zn/HY, Ru-Cu/HY, and Ru-Ni/HY cases, and since Ru-Cu/HY
and Ru-Ni/HY were found to be higher in NH3 uptake, they may
associate with the stronger acid sites preferentially.
X-ray spectroscopy, as dipicted in Figure S2. Moreover, the XRD
reflections indicate indirectly a synergistic effect of a second metal
in bimetallic Ru–M (M= Fe, Ni, Cu, Zn) catalysts. The addition of
a second metal has definitely changed the morphology and the
crystalline nature of the Ru present in the HY zeolite, as
evidenced from Figure 4. Also, the relative intensity of the peaks
such as 2θ=43.8° was reduced when compared to the pure Ru-
supported catalyst, indicating the well-dispersed nature of the
bimetallic catalysts. These reflections indicate that the addition of
a second metal to Ru would have enabled Ru to form much
smaller particles that are mixed with the second metal after the
hydrogen reduction.
Figure 3.NH3-TPD curves of the synthesized bifunctional
The phase and phase composition of the prepared catalysts
were determined by XRD, as shown in Figure 4. The XRD
patterns of all the prepared bifunctional catalysts in the range of
2θ=10° to 2θ=33°are similar, with a majority of the peaks in this
range being assigned to the typical FAU structure of HY zeolite[35]
,
indicating that the impregnation of metals in the support has no
obvious effect on the parent zeolite structure. After impregnation,
calcination, and reduction, metal species as well as their oxides
might exist within the HY zeolite structure. The presence of
formed reduced metals and metal oxides was not obvious from
XRD patterns as compared with the signals of HY zeolite. This
result is in accordance with previous investigations which have
revealed that the diffraction signals of metal and metal oxide
particles could not easily be observed upon incorporation into the
zeolite structure when the metal loading was low,[35a,36] or the
metal oxides might be present as non-crystalline phases.[36]
Besides, good dispersion of metal species and limited
segregation of the related oxide particles could also obscure the
metal and metal oxides species from being observed with XRD.[37]
Although the XRD signals of metal and metal oxides within the
bimetallic catalysts are not as intense as that of HY support, they
are evident enough to show the existence of different metals and
metal oxides in different synthesized catalysts, as shown in Figure
4 (2θ=33° to 2θ=50°). The existence of these bimetallic particles
in the prepared catalysts was further verified by energy-dispersive
Figure 4. XRD patterns for the synthesized bifunctional catalysts.
As indicated by the XRD, a part of the 3d transition metals
within the bimetallic catalysts were not totally reduced, with some
remaining metal oxides present in the acidic support of HY zeolite.
Both the acidic HY zeolite and the metal oxides can catalyze
reactions that eliminate some of the oxygenated functionalities
while building up the C–C chain.[38] For instance, ketonization,
oligomerization, and transalkylation of methoxy groups, catalyzed
by acids and oxides, maximize the fraction of carbon that is
ultimately retained in the liquid product.[38] Moreover, Montassier
and co-authors suggest that Cu metal has a higher adsorption
capacity for polar fractions (including hydroxyl group and ether
bonds) due to its electrophilicity, and this adsorption leads to a
weakening of the O-H and C-O bond. This propensity for
adsorbing polar fractions might be enhancedwhen Cu associated
with noble metals or metals with a lower d orbital electron
This article is protected by copyright. All rights reserved.

10.1002/cssc.201700160
ChemSusChem
FULL PAPER
occupancy, which can accept electrons from Cu, lead to an
increase in the Cu atom’s electrophilicity,[25] This phenomenon
can possibly account for the higher HDO reactivity of Ru-Cu/HY
catalyst than the other catalysts.
The morphology and microstructure of the synthesized
bifunctional catalysts were investigated by STEM, as shown in
Figure 5. The average metal particle size for the monometallic
catalyst of Ru/HY is about 10~15 nm (Figure 5, a) which is larger
than that supported on other materials reported in previous
studies.[11g,22,25] Ru metal particles tend to form compact clusters
with diameters of approximately 50 nm (Figure 5, b).We have
found that bimetallic nanoparticles have smaller average sizes
monometallic Ru particles with bimetallic clusters indicate the
existence of strong synergetic effects between Ru and the
investigated inexpensive earth abundant transition metals, which
can prevent Ru from serious self-aggregation. It is well known that
the catalytic activity of a supported metal catalyst is highly
dependent on the metal particle/cluster size and metal
particle/cluster morphology.[39] Metal particles/clusters with small
size or incompact structure have large fractions of the atoms
exposed on the surface to reactants, resulting in high/unique
catalytic activities. The Ru–Cu bimetallic nanoparticles on HY are
in a good dispersion without serious aggregation. The STEM
results are quite consistent with the XRD characterization of these
catalysts.
All of the aforementioned factors (e.g., large surface
area/small particle size, high total and strong acid sites, and
bimetallic nanoparticles with high dispersion) could contribute to
change/improve the activity of the bimetallic catalysts for the
hydrodeoxygenation conversion of lignin and its model
compounds.
X-ray Photoelectron Spectroscopy (XPS) was performed on
the Ru-based bimetallic catalysts. XPS is a surface sensitive
technique which has a nominal sampling depth of ~4 nm. High
energy resolution photoemission spectra of the Ru3d5/2, Ru3d3/2
and C1s regions are shown in Figure S3.. The Binding Energy
(BE) of the Ru 3d5/2 line after charge correction referencing the Al
2p line at 74.7 eV is 279.9 ±0.2 eV. This is consistant with Ru0 or
41]
bimetalic Ru as reported in the literature.[40,
The Ru 3d3/2
component should be about 4.2 eV higher binding energy which
overlaps the C 1s lines.High energy resolution photoemission
spectra of the Fe 2p3/2, Ni 2p, Cu 2p, and Zn 2p3/2 regions from
catalysts Ru-Fe-HY, Ru-Ni/HY, Ru-Cu/HY and Ru-Zn/HY
respectively are shown in Figure S4. The BE of the Fe 2p3/2 line
from Ru-Fe/HY is 711.8 eV consistant with Fe+3.[41] The BE of the
Ni 2p3/2 line for Ru-Ni/HY is 456.7 eV, consistant with Ni+3 [41]. The
BE for the Cu 2p3/2 line is 933.6 eV and the shake-up lines at ~942
eV is consistant with Cu+2.[41] For Ru-Zn/HY the BE for the Zn 2p3/2
line is 1022.9 eV.
Conclusions
Bifunctional catalysts Ru/HY and Ru-M/HY (M= Fe, Ni, Cu, Zn)
were synthesized and evaluated on HDO conversion of softwood
lignin as well as several lignin model compounds. Results
obtained from guaiacol HDO conversion indicate that all the
bimetallic catalysts, especially Ru-Cu/HY, exhibited better HDO
catalytic activities (regarding guaiacol conversion and
hydrocarbon yield) as compared with Ru/HY. The combination of
a 3d transition metal (Fe, Ni, Cu, Zn) with Ru can modulate the
hydrogenolysis activity of Ru and help to prevent the hydrocarbon
products from being over-hydrogenolysis to form gaseous
products. Results from conversion of other lignin model
compounds and softwood lignin also revealed the high HDO
catalytic activity of the prepared bimetallic catalysts. The yield of
hydrocarbon products over the synthesized bifunctional catalysts
was higher than that over the combination mixing catalyst of
Ru/Al2O3 and HY zeolite, which could be probably ascribed to the
Figure 5.HAADF-STEM images of the prepared zeolite supported Ru-based
catalysts. (a-b) Ru/HY, (c) Ru-Fe/HY, (d) Ru-Ni/ HY, (e) Ru-Cu/ HY, (f) Ru-
Zn/HY.
and narrower size distribution as compared with those of
monometallic Ru nanoparticles. The metal particle sizes are
about 2~5 nm, 3~6 nm, 6~8 nm, and 8~10 nm for Ru-Cu/HY, Ru-
Ni/ HY, Ru-Fe/HY, and Ru-Zn/HY catalysts, respectively.
Bimetallic clusters are found, however with much smaller
diameters. Moreover, the morphology of these bimetallic clusters
is quite different from that of ruthenium monometallic particles.
For example, the bimetallic Ru-Cu clusters are rather loose
(Figure. 5, e), probabaly due to that ruthenium and copper are
immiscible in the bulk.[24]The different size and morphology of
This article is protected by copyright. All rights reserved.

10.1002/cssc.201700160
ChemSusChem
FULL PAPER
intimacy criterion. These catalysts were characterized by BET,
NH3-TPD, XRD, and STEM to study the structure-catalytic activity
relationship. Results revealed that Ru-Cu/HY has both higher acid
volume and larger ratio of stronger acid sites as compared to
other prepared bifunctional catalysts. XRD test indicated that the
impregnation of metals in the HY support has little effect on the
parent zeolite structure. Moreover, XRD and STEM results
suggested that the addition of a second metal to Ru enabled Ru
to form smaller size particles. The morphology of the bimetallic
clusters was found to be quite different (smaller average size and
narrow size distribution) from that of monometallic particles as
indicated by STEM. Further study on the alloying effect of
ruthenium metal with Fe, Ni, Cu, and Zn is in progress.
suspension was stirred for 24 h at room temperature followed by
evaporation of the excess water at 55oC. The obtained solids
o
were dried at 120 C and calcined at 550 oC for 4 h with a ramp
up of temperature of 10 oC /min under air sparging. The catalysts
were reduced at 250 oC for 2 h under 2 MPa H2 before use.
Catalyst characterization: The catalytic materials synthesized in
this work were characterized by X-ray diffraction (XRD), scanning
transmission electron microscopy (STEM), N2 physisorption using
the Brunauer-Emmett-Teller (BET), and NH3 temperature
programmed desorption (TPD). X-ray diffraction (XRD) patterns
were taken with a Bruker D8 Venture diffractometer equipped with
Cu tube operated at 40 W (40 kV, 1 mA). High-angle annular dark-
field (HAADF) scanning transmission electron microscopy
(STEM) images were taken on a probe-corrected FEI Titan 80-
300 S/TEM operating at 300 kV.
Experimental section
X-Ray Photoelectron Spectroscopy was perfromed using a
Physical Electronics Quantera Scanning X-ray Microprobe. This
system uses a focused monochromatic Al Kα X-ray (1486.7 eV)
source for excitation and a spherical section analyzer. The
instrument has a 32 element multichannel detection system. The
X-ray beam is incident normal to the sample and the
photoelectron detector is at 45° off-normal. High energy resolution
spectra were collected using a pass-energy of 69.0 eV with a step
size of 0.125 eV. For the Ag 3d5/2 line, these conditions produced
a FWHM of 1.0 ± 0.1 eV. The binding energy scale is calibrated
using the Cu 2p3/2 feature at 932.62 ± 0.05 eV and Au 4f7/2 at 83.96
± 0.05 eV. Spectra have been charge corrected to the Al 2p line
at 74.7 eV. [42]
Materials: Ruthenium (III) chloride hydrate (RuCl3·xH2O, Ru
content 37 wt%), anhydrous zinc (II) chloride (ZnCl2, Zn content
48.02 wt%), anhydrous cuprous (II) chloride (CuCl2, Cu content
47.28 wt%), nickel (II) chloride hydrate (NiCl2·6H2O, 98% purity,
Ni content 24.71 wt%) and ferric (III) chloride hydrate (FeCl3·6H2O,
98% purity, Fe content 20.67 wt%) were purchased from Fisher
Scientific. Guaiacol, diphenyl ether, benzofuran and
(benzyloxy)benzene were purchased fromSigma-Aldrich. Lignin
was isolated from Lodgepole Pine sawdust using
flowthroughpretreatment. Zeolite HY (CBV 400) was purchased
from Zeolyst International.
N2 physisorption analysis for determination of surface area and
mesopore size was carried out using a Micromeritics ASAP2020
volumetric analyzer at liquid nitrogen temperature (77 K). The
surface area was calculated by Brunauer-Emmett-Teller (BET)
equation from the adsorption data obtained at P/P0 values
between 0.05 and 0.2. The average mesopore size was
determined from the adsorption branch of the isotherm using the
Barrett-Joyner-Halenda (BJH) algorithm. NH3 temperature-
programmed desorption (NH3-TPD) measurements were
performed in a quartz tube reactor equipped with a thermal
conductivity detector (TCD). The samples (~50 mg) were
degassed in a cell under pure He gas flow (50 mL/min) at 700oC
for 2 h (ramping rate = 10 oC /min) to remove the possible Si-OH
groups that can potentially decompose by dehydration and
formation of water. Then, the samples were treated with the O2
flowing (10 mL/min) for 1 h, purged with pure He for 15 min, and
treated with H2 flow (10 mL/min) for 1 h. The samples were cooled
down to ambient temperature in the cell under pure He flow and
exposed to NH3 gas for 20 min. After adsorption of NH3 gas, the
samples were purged with pure He flow for 30 min, and
subsequently the cell was heated to 700oC for NH3 the TPD
measurements. The desorbed NH3 molecules were monitored
using a thermal conductivity detector (TCD) upon increase of
temperature of the samples.
Lignin isolation and purification: Softwood samples containing
0.5 g dry weight mass were loaded into flowthrough tubular
reactors with 20.5 ml working volumes and stainless steel porous
frits. The flowthrough reactors were then connected to an HPLC
pump and a fluidized sand bath system (model SBL-2D, Omega
engineering, Inc., CT). 0.05% (w/w) sulfuric acid at room
temperature was pumped through the reactor to purge the
entrained air. Then, the reactors were pressurized to a set
pressure of 300 psi–700 psi. The loaded biomass was completely
wetted by this procedure. The reactors were heated to 250oC by
plunging the pre-heating coil and reactors into a 4-kW fluidized
sand bath. The temperature of the sand bath was set to 15oC
higher than the target reaction temperature. The flow rate was set
at 25 mL/min. After 8 min of pretreatment, the reactors were
cooled immediately by immersion in cold water. At this flow rate,
the average temperature of the dilute sulfuric acid in the reactor
tubes was measured at the target temperature. The liquid
collected through the pretreatment was centrifuged at 1000 rpm,
and the flowthrough lignin precipitate was washed with DI water
by centrifuging at 1000 rpm. The precipitated lignin sample was
freeze-dried and stored at room temperature for further use.
Catalyst preparation: Monometallic catalyst of Ru/HY with a Ru
loading of 5 wt% and bimetallic Ru-M/HY (M=Fe, Ni, Cu, Zn)
catalysts with each metal loading of 2.5 wt% were prepared by
using a conventional incipient wetness impregnation procedure
with aqueous solutions of the metals salts.11h The resultant
Catalytic hydrodeoxygenation (HDO) reactions: In a typical
reaction, lignin or lignin model compound (100 mg), water (30 mL)
and catalyst (100 mg) were added to a Parr reactor (reactor
This article is protected by copyright. All rights reserved.

10.1002/cssc.201700160
ChemSusChem
FULL PAPER
volume= 100 mL). The reactor was sealed and purged with
H2three times, and then pressurized with 4 MPa H2 (room
temperature). The reactions were carried out at 250 oC for 2 or 4
h. After each reaction, the reactor was cooled to room
temperature to quench the reaction by immersing in a cold water
bath. n-decane (5 μL) was added to the reaction solution and used
as an internal standard for hydrocarbons calibrations. Ethyl
acetate (30 mL) was used to extract the products from the
reaction solution. After centrifugation at a speed of 10000 rpm for
10 min, the extract was separated and analyzed by GC and GC-
MS. The aqueous phase was filtered to recover the solids which
were made up of unreacted lignin, catalyst, and char. The solids
were washed with DI water and then ethanol (each for three
times). After that, the washed solids were dried at 105 oC for 24 h
and weighed.
Renewable Energy Laboratory Subcontract # AEV-6-52054-01
under Prime U.S. Department of Energy (DOE) Award # DE-
AC36-08G028308 with the Bioproducts, Science & Engineering
Laboratory and Department of Biological Systems Engineering
at Washington State University. This work was performed in
part at the William R. Wiley Environmental Molecular Sciences
Laboratory (EMSL), a national scientific user facility sponsored
by the U.S. Department of Energy’s Office of Biological and
Environmental Research and located at the Pacific Northwest
National Laboratory, operated for the Department of Energy by
Battelle. The authors would like to thank Ms. Marie S. Swita who
helped us to collect part of GCMS data for this project.
Keywords: Lignin • bimetallic catalyst • bifunctional catalysts
Lignin deconstruction products analysis: The organic solvent
extracted samples (1 μL ) were injected into a stream of He
(carrier gas) flowing at 0.6 mL min−1 into a DB-5 (30 m length ×
250 μm I.D. × 0.25 μm film thickness, J&W Scientific) capillary
column fitted in an Agilent Technologies 7890A GC system set in
the splitless mode. The GC oven was programmed to reach 45°C
and soak for 2 min; then ramp up at the rate of 15°C per min until
the temperature reached 200°C and held at this temperature for
1 min, after which the temperature was raised at the rate of
5°C/min until the temperature reached 280°C, where it was held
at the final temperature for 7 min. Eluting compounds were
detected with an MS (Agilent Technologies 5975C) inert XL EI/CI
MSD with a triple axis detector, and compared using NIST
libraries. Shimadzu TOC-V Analyzer was used to quantify the total
organic carbon of the lignin and residue solids (including catalyst
and residue lignin). The effective carbon number (ECN) approach
can be used for calculating relative response factors in cases
where pure standard materials are not available for detector
calibration.20 Lignin conversion, the mass yield of each product
and its selectivity were calculated as follows:
•hydrodeoxygenation • biofuel • jet fuel
[1]
[2]
a) C. Li, X. Zhao, A. Wang, G. W. Huber, T. Zhang,Chem. Rev. 2015,15,
11559–11624;b) J. Zakzeski, P. C. A. Bruijnincx, A. L. Jongerius, B. M.
Weckhuysen,Chem. Rev. 2010, 110, 3552-3599.
A. J. Ragauskas, G. T. Beckham, M. J. Biddy, R. Chandra, F. Chen, M.
F. Davis, B. H. Davison, R. A. Dixon, P. Gilna, M. Keller, P. Langan, A.
K. Naskar, J. N. Saddler, T. J. Tschaplinski, G. A. Tuskan, C. E. Wyman,
Science 2014, 344, 709-719.
[3]
a) H. Wang, T. Deng, H. Ruan, X. Hou, J. R. Cort, B. Yang, Green Chem.
2016,18, 2802-2010;b) H. Wang, H. Ruan, H. Pei, H. Wang, X. Chen, M.
p Tucker, J. R. Cort, B. Yang,Green Chem. 2015,17, 5131-5135;c) S.
Van den Bosch, W. Schutyser, R. Vanholme, T. Driessen, S.-F.
Koelewijn, T. Renders, B. De Meester, W. Huijgen, W. Dehaen, C.
Courtin,Energy Environ. Sci. 2015, 8, 1748-1763;d) P. J. Deuss, M. Scott,
F. Tran, N. J. Westwood, J. G. de Vries, K. Barta, J. Am. Chem. Soc.
2015, 8, 7456-7467;e) M. Zaheer, R. Kempe,ACS Catal. 2015, 5, 1675-
1684.
[4]
[5]
P. C. Bruijnincx, R. Rinaldi, B. M. Weckhuysen,Green Chem. 2015, 17,
4860-4861.
a) Z. Luo, Y. Wang, M. He, C. Zhao,Green Chem. 2016, 18, 433-441;b)
D. D. Laskar, B. Yang, H. M. Wang, J. Lee,Biofuel. Bioprod. Bior. 2013,
7, 602-626.
For the conversion of lignin model compounds:
[6]
[7]
a) E. Laurent, B. Delmon,J. Catal. 1994, 146, 281-291;b) D. C.
Elliott,Energy Fuel. 2007, 21, 1792-1815.
Conversion=
ꢀꢁꢂꢃꢄꢅ ꢆꢇ ꢂꢈꢂꢅꢂꢉꢊ ꢋꢆꢌꢁꢊ ꢍꢆꢋꢎꢆꢏꢈꢌꢐꢑꢒꢁꢂꢃꢄꢅ ꢆꢇ ꢓꢁꢋꢉꢂꢈꢂꢈꢃ ꢋꢆꢌꢁꢊ ꢍꢆꢋꢎꢆꢏꢈꢌꢐ
ꢔ
ꢀꢁꢂꢃꢄꢅ ꢆꢇ ꢂꢈꢂꢅꢂꢉꢊ ꢋꢆꢌꢁꢊ ꢍꢆꢋꢎꢆꢏꢈꢌꢐ
a) F. P. Bouxin, A. McVeigh, F. Tran, N. J. Westwood, M. C. Jarvis, S. D.
Jackson,Green Chem. 2015, 17, 1235-1242;b) C. Zhao, J. A.
Lercher,ChemCatChem 2012, 4, 64-68.
100%
ꢀꢁꢂꢃꢄꢅ ꢆꢇ ꢎꢓꢆꢌꢏꢍꢅ ꢕ
Distributionx=ꢀꢁꢂꢃꢄꢅ ꢆꢇ ꢅꢆꢅꢉꢊ ꢎꢓꢆꢌꢏꢍꢅꢐ ꢌꢁꢅꢁꢍꢅꢁꢌ ꢔ 100%
[8]
[9]
O. Jan, R. Marchand, L. C. Anjos, G. V. Seufitelli, E. Nikolla, F. L.
Resende,Energy Fuel. 2015, 29, 1793-1800.
For the conversion of lignin:
P. Ruiz, K. Leiva, R. Garcia, P. Reyes, J. Fierro, N. Escalona,Appl. Catal.
A-Gen. 2010,384, 78-83.
Conversion=ꢖꢉꢓꢗꢆꢈ ꢍꢆꢈꢅꢁꢈꢅ ꢂꢈ ꢆꢓꢂꢃꢂꢈꢉꢊ ꢊꢂꢃꢈꢂꢈꢑꢍꢉꢓꢗꢆꢈ ꢍꢆꢈꢅꢁꢈꢅ ꢂꢈ ꢓꢁꢐꢂꢌꢏꢁ ꢐꢆꢊꢂꢌ ꢔ
ꢖꢉꢓꢗꢆꢈ ꢍꢆꢈꢅꢁꢈꢅ ꢂꢈ ꢆꢓꢂꢃꢂꢈꢉꢊ ꢊꢂꢃꢈꢂꢈ
[10] C. R. Lee, J. S. Yoon, Y. W. Suh, J. W. Choi, J. M. Ha, D. J. Suh, Y. K.
Park, Catal. Commun. 2012, 17, 54-58.
100%
[11] a)N. Yan, C. Zhao, P. J. Dyson, C. Wang, L. t. Liu, Y. Kou,
ChemSusChem 2008, 1, 626-629;b) T. Omotoso, S. Boonyasuwat, S. P.
Crossley,Green Chem. 2014, 16, 645-652;c) C. Michel, P. Gallezot,ACS
Catal. 2015, 5, 4130-4132;d) A. Kloekhorst, H. J. Heeres,ACS Sustain.
Chem. Eng. 2015, 3, 1905-1914;e) G. Yao, G. Wu, W. Dai, N. Guan, L.
Li, Fuel 2015,150, 175-183;f) Y. Liu, L. Chen, T. Wang, Q. Zhang, C.
Wang, J. Yan, L. Ma,ACS Sustain. Chem. Eng. 2015, 3, 1745-1755;g) S.
Iqbal, S. Kondrat, D. R. Jones, D. Schoenmakers, J. K. Edwards, L. Lu,
B. R. Yeo, P. P. Wells, E. K. Gibson, D. J. Morgan,ACS Catal. 2015, 5,
5047-5059;h) W. Zhang, J. Chen, R. Liu, S. Wang, L. Chen, K. Li, ACS
Sustain. Chem. Eng. 2014, 2, 683-691.
ꢜꢉꢐꢐ ꢝ_ꢞꢟꢠꢡꢝꢟ
ꢢꢣꢤ
ꢉꢓꢁꢉꢕ/ ꢥꢖꢦꢕ
ꢔ
ꢔ MWꢘ
ꢉꢓꢁꢉ ꢝ_ꢞꢟꢠꢡꢝꢟ/ ꢢꢧ
Yieldꢘ ꢙwt%ꢚ ꢛ
Mass ꢨꢩꢪꢫꢩꢫ
ꢤꢬ
∑
Total product yield= ꢕꢭꢢ Yieldꢘ
Acknowledgements
This work was supported by the Sun Grant-U.S. Department of
Transportation (DOT) Award # T0013G-A- Task 8, and National
[12] D. D. Laskar, M. P. Tucker, X. Chen, G. L. Helms, B. Yang,Green Chem.
2014, 16, 897-910.
This article is protected by copyright. All rights reserved.

10.1002/cssc.201700160
ChemSusChem
FULL PAPER
[13] J. Zhang, J. Teo, X. Chen, H. Asakura, T. Tanaka, K. Teramura, N.
Yan,ACS Catal. 2014, 4, 1574-1583.
[28] a) X. Wang, R. Rinaldi,ChemSusChem 2012,5, 1455-1466;b) J. He, C.
Zhao, D. Mei, J. A. Lercher, J. Catal. 2014,309, 280-290.
[29] Y.-R. Luo, Comprehensive handbook of chemical bond energies. CRC
press: 2007.
[14] W. Yu, M. D. Porosoff, J. G. Chen,Chem. Rev. 2012, 112, 5780-5817.
[15] Y. L. Qin, Y. C. Liu, F. Liang, L. M. Wang,ChemSusChem 2015, 8, 260-
3.
[30] E. Furimsky,Appl. Catal. A-Gen. 2000,199, 147-190.
[31] J. Zecevic, G. Vanbutsele, K. P. de Jong, J. A. Martens,Nature 2015,528,
245-248.
[16] J. R. Kitchin, J. K. Nørskov, M. A. Barteau, J. Chen, J. Phys. Rev. Lett.
2004, 93, 156801.
[17] a) A. Vjunov, M. Y. Hu, J. Feng, D. M. Camaioni, D. Mei, J. Z. Hu, C.
Zhao, J. A. Lercher,Angew. Chem. Int. Ed. 2014, 53, 479-482;b) K. Na,
S. Alayoglu, R. Ye, G. A. Somorjai,J. Am. Chem. Soc. 2014, 137, 17207-
17212;c) K. Chen, J. Damron, C. Pearson, D. Resasco, L. Zhang, J. L.
White,ACS Catal. 2014, 4, 3039-3044;d) M. Bregolato, V. Bolis, C. Busco,
P. Ugliengo, S. Bordiga, F. Cavani, N. Ballarini, L. Maselli, S. Passeri, I.
Rossetti, J. Catal. 2007, 245, 285-300.
[32] a) P. Ferrin, S. Kandoi, A. U. Nilekar, M. Mavrikakis, Surf.Sci. 2012, 606,
679-689. b) N. Batalha, L. Pinard, C. Bouchy, E. Guillon, M. Guisnet, J.
Catal. 2013,307, 122-131.
[33] J. Kim, W. Kim, Y. Seo, J.-C. Kim, R. Ryoo, J. Catal. 2013,301, 187-197.
[34] a) A. Pelzer, M. R. Sturgeon, A. W. Yanez, G. Chupka, M.-K. R. O'Brien,
R. Katahira, R. Cortright, L. Woods, G. T. Beckham, L. J. Broadbelt,ACS.
Sustain. Chem. Eng. 2015,3, 1339-1347;b) C. A. Monteiro, D. Costa, J.
L. Zotin, D. Cardoso, Fuel 2015,160, 71-79;c) A. Kaiho, M. Kogo, R.
Sakai, K. Saito, T. Watanabe,Green Chem. 2015,17, 2780-2783.
[35] a) N. A. S. Ramli, N. A. S. Amin,Appl. Catal. B-Environ. 2015,163, 487-
498;b) R. Malyala, C. Rode, M. Arai, S. Hegde, R. Chaudhari,Appl. Catal.
A-Gen. 2000,193, 71-86.
[18] a) Y. Yu, X. Li, L. Su, Y. Zhang, Y. Wang, H. Zhang,Appl.Catal. A-Gen.
2012, 447, 115-123;b) L.-T. Liu, B. Zhang, J. Li, D. Ma, Y. Kou,Acta Phys.
Chim. Sin. 2012, 28, 2343-2348;c) S.-S. Kim, H. W. Lee, R. Ryoo, W.
Kim, S. H. Park, J.-K. Jeon, Y.-K. Park,J. Nanosci. Nanotechno. 2014,
14, 2414-2418;d) H. Ben, A. J. Ragauskas,RSC Adv. 2012, 2, 12892-
12898;e) A. K. Deepa, P. L. Dhepe,ACS Catal. 2014, 5, 365-379.
[19] L. Guczi, I. Kiricsi,Appl. Catal. A-Gen. 1999, 186, 375-394.
[20] J. T. Scanion, D. E. Willis, Chromatogr. Sci.1985, 23, 333-340.
[21] J. Sun, A. M. Karim, H. Zhang, L. Kovarik, X. S. Li, A. J. Hensley, J.-S.
McEwen, Y. Wang,J. Catal. 2013,306, 47-57.
[36] S. Shwan, J. Jansson, L. Olsson, M. Skoglundh, Catal. Sci. Technol.
2014,4, 2932-2937.
[37] M. Usman, D. Li, R. Razzaq, M. Yaseen, C. Li, S. Zhang,J. Ind. Eng.
Chem. 2015,23, 21-26.
[38] S. Boonyasuwat, T. Omotoso, D. E. Resasco, S. P. Crossley, Catal. lett.
2013,143, 783-791.
[22] X. Dai, J. Liang, D. Ma, X. Zhang, H. Zhao, B. Zhao, Z. Guo, F. Kleitz, S.
Qiao,Appl. Catal. B-Environ. 2015,165, 752-762.
[39] a) Z. Xu, F.-S. Xiao, S. Purnell, O. Alexeev, S. Kawi, S. Deutsch, B.
Gates,Nature 1994, 372, 346-348;b) B. Gates, Chem. Rev. 1995,95,
511-522.
[23] B. Hammer, J. K. Nørskov,Adv. Catal. 2000,45, 71-129.
[24] J. G. Chen, C. A. Menning, M. B. Zellner,Surf. Sci. Rep. 2008,63, 201-
254.
[40] A. Lewera, W. P. Zhou, C. Vericaa, J. H. Chung, R. Haasch, A.
Wieckowski, P.S. Bagus, Electrochim. Acta 2006, 51, 3950-3956
[41] J. F. Moulder, W. F. Stickle, P. E. Sobol, K. D. Bomben, “Handbook of X-
ray Photoelectron Spectroscopy”, ULVAC-PHI. Inc. 1995.
[42] L. A. Pedersen, J. H. Lunsford, J. Catal. 1980, 61, 39-47.
[25] J. B. Salazar, D. D. Falcone, H. N. Pham, A. K. Datye, F. B. Passos, R.
J. Davis,Appl. Catal. A-Gen. 2014,482, 137-144.
[26] C. R. Lee, J. S. Yoon, Y.-W. Suh, J.-W. Choi, J.-M. Ha, D. J. Suh, Y.-K.
Park,Catal. Commun. 2012,17, 54-58.
[27] Y.-C. Lin, C.-L. Li, H.-P. Wan, H.-T. Lee, C.-F. Liu, Energy Fuel. 2011,25,
890-896.
This article is protected by copyright. All rights reserved.

10.1002/cssc.201700160
ChemSusChem
FULL PAPER
Entry for the Table of Contents
FULL PAPER
Lignin to advanced bio-fuels: High
yields (26 wt% to 32 wt%) of alkanes
in jet fuel or diesel range have been
directly produced from aqueous
phase hydrodeoxygenation (HDO)
conversion of softwood lignin by the
catalysis of Ru-based bimetallic
catalysts supported on zeolite Y.
These bimetallic and
bifunctionalcatalysts showed high
efficiency as compared with the
combination catalysts of Ru/Al2O3
and HY zeolite.
Hongliang Wang, Hao Ruan, Maoqi
Feng, Yuling Qin, Heather Job, Langli
Luo,Chongmin, Wang,Mark H.
Engelhard Erik Kuhn,Xiaowen
Chen,Melvin P. Tucker, and Bin Yang*
Page No. – Page No.
Hydrodeoxygenation of Lignin to
liquid alkanes on Ru-based
Bimetallic CatalystsSupported on
Zeolite Y
This article is protected by copyright. All rights reserved.