Insights into the role of nanoalloy surface compositions toward catalytic acetone hydrogenation

Article abstract of DOI:10.1039/c8cc04293d

A significant composition-dependent catalysis behavior was observed in catalytic acetone hydrogenation. Carbon supported PtRu alloy nanoparticles (NPs) with optimal surface composition achieved ultra-efficient and highly selective production of isopropyl alcohol.

Full text of DOI:10.1039/c8cc04293d

View Article Online
View Journal
ChemComm
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: Z. Yang, H. Zhu,
H. Zhu, Y. Wang, L. Che, Z. Yang, J. Fang, Q. Wu and B. H. Chen, Chem. Commun., 2018, DOI:
10.1039/C8CC04293D.
This is an Accepted Manuscript, which has been through the
Volume 52 Number
1 4 January 2016 Pages 1–216
Royal Society of Chemistry peer review process and has been
accepted for publication.
ChemComm
Accepted Manuscripts are published online shortly after
Chemical Communications
www.rsc.org/chemcomm
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 1359-7345
COMMUNICATION
Marilyn M. Olmstead, Alan L. Balch, Josep M. Poblet, Luis Echegoyenet al.
Reactivity differences of Sc3N@C2n (2n 68 and 80). Synthesis of the
first methanofullerene derivatives of Sc N@D5h-C80
=
3
rsc.li/chemcomm

Please do not adjust margins
ChemComm
Page 1 of 5
View Article Online
DOI: 10.1039/C8CC04293D
Journal Name
COMMUNICATION
Insights into the role of nanoalloy surface composition toward
catalytic acetone hydrogenation†
Received 00th January 20xx,
Accepted 00th January 20xx
a
a
Zhao Yang a*, Huaze Zhu b, Huijuan Zhu , Yanbing Wang a, liming Che *, Zhiqing Yang b*, Jun
c
c
Fang , Qi-Hui Wu , Bing Hui Chen a*
DOI: 10.1039/x0xx00000x
www.rsc.org/
A
significant composition-dependent catalysis behavior was isopropyl alcohol) fuel cells, which require a higher selectivity
observed in catalytic acetone hydrogenation. Carbon supported to isopropyl alcohol at high conversion than that presently
PtRu alloy nanoparticles (NPs) with optimal surface composition available.13-15 There are a range of heterogeneous or
achieved ultra efficient and highly selective production of homogeneous catalysts reported in acetone hydrogenation
isopropyl alcohol.
(Table S1†). However, more efforts towards the production of
isopropyl alcohol with an efficient but green method should be
Rational design of highly effective heterogeneous catalyst continuously demonstrated. Herein, we report the surface
depends on the fundamental understanding of the structure- composition-controlled carbon supported PtRu nanoalloy
property relationship in catalysis. Since the properties of the catalyst for enhancing catalytic performance in acetone
catalyst surfaces are closely correlated with the catalytic hydrogenation. It is worth mentioning that such present
performance, the precise modification of the metallic catalyst system shows green process and unexpected high efficiency
surface by introducing another component could facilitate the relative to most of the current records (see ESI†). Catalytic
controlled tuning of the performance.1-12 Generally, alloy activity and selectivity exhibit evident dependence on the
materials have distinct binding properties with reactants in atomic scale distribution of surface Pt and Ru sites, this
contrast to those for monometallic materials.11 Addition of composition-dependent behavior results from the essential
another metal can alter the availability of active surface sites distinction of functionality between these two metals on
(i.e., the ensemble effect) or the binding strength of reactants, activating the reactants, and their complementary advantages
intermediates, products, and spectator species (i.e., the in catalysis. Moreover, hydrogenation of 3-pentanone was also
electronic and/or strain effect).12 The ratio between alloying studied to underline the potential of the catalyst and such
components plays an important role in defining the physical composition effect it could have on other carbonyl
and chemical properties of alloy materials,10 a study on the hydrogenation (of ketones) reactions.
surface chemistry and catalytic properties of the alloy catalysts
with various compositions would be an important supplement fixed total theoretical metal loading but with various respective
to elucidate the underlying structure-property relationship. metal contents were prepared via a surfactant-free ethylene glycol
A series of carbon black supported Pt-Ru bimetallic catalysts with
Catalytic hydrogenation of carbonyl groups is one of the reduction process (labeled as xPtyRu/C, where x and y denote the
most useful and widely applicable reactions routes for organic theoretical weight percentage loading of Pt and Ru, percentage sign
synthesis.8 In particular, acetone hydrogenation to isopropyl was removed, see ESI†). These as-obtained bimetallic samples with
alcohol (C=O hydrogenation), plays important roles and has seven different compositions show the similar structure of N2
been applied in the renewable energy technology such as the adsorption-desorption isotherms (Fig.S2†). Parameters including
chemical heat pumps (isopropyl alcohol-acetone-hydrogen the BET surface area, total pore volume and average pore diameter
chemical heat pump), H2 storage schemes and DIPA (direct are smaller than those of the parent catalyst’s support, owing to the
introduction of the guest metal NPs into the hole structure (Table
S2†). As shown in Fig.1a, 3Pt/C and 3Ru/C exhibit the existence
of typical metallic diffraction peaks which are indicative of the
crystalline structure of metallic bulk Pt and Ru respectively by
comparing with the reference patterns (ICDD-JCPDS Card No.
040802 and No.06-0663). Compared with Pt (111) in 3Pt/C, as
the added Ru component’s proportion in metal loading
increases, the shape of the strongest diffraction peak in
aDepartment of Chemical and Biochemical Engineering, National Engineering
Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry
and Chemical Engineering, Xiamen University, Xiamen 361005, China. Email:
zyang@stu.xmu.edu.cn (Z. Yang), lmc@xmu.edu.cn (L.M. Che),
chenbh@xmu.edu.cn (B.H. Chen)
bShenyang National Laboratory for Materials Science, Institute of Metal Research,
Chinese Academy of Sciences, Shenyang 110016, China. Email: yangzq@imr.ac.cn
(Z.Q. Yang)
cCollege of Chemical Engineering and Materials Science, Quanzhou Normal
University, Quanzhou 362000, China.
†Electronic Supplementary Information (ESI) available. See DOI:
10.1039/x0xx00000x
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 2 of 5
View Article Online
DOI: 10.1039/C8CC04293D
COMMUNICATION
Journal Name
(i.e., a dilatation of the original lattice) of the original pure Ru
lattice.16 Fig.1c shows the elemental line-scan and mapping
analysis results. The curve of intensity variation of Pt is similar
in shape with that of Ru (line-scan analysis). Mapping results
demonstrate that such two kinds of elements are uniformly
mixed in Pt-Ru NPs due to the alloy formation.
A “V”-type variation behaviour with increased loading ratio
of Pt to Ru is observed on metal particle diameter (Table S2†),
which is consistent with the trend of shape variation in XRD
diffraction peak described above. Many literatures reported
the similar phenomenon that introduction of a second metal
component can lead to the increase of bimetallic particle
dispersion which attributes to the interplay between the two
metal components.4,17-18 In this study, such interaction derives
from the alloy formation. Pt and Ru atoms diffuse into each
other’s lattice, the uniform mixing and mutual contact provide
the availability for their interplay. When the proportion of
second metal component in loading increases, the contact
range between such two types of metal atoms would be
enlarged and consequently leads to their interaction being
strengthened, thus resulting in the metal particle dispersion
further increase.
As two kinds of important solid surface analysis techniques,
High-sensitivity low-energy ion-scattering spectroscopy (HS-
LEISS) has an outstanding sensitivity toward the outermost
atomic layer, whereas X-ray photoelectron spectroscopy (XPS)
can probe the composition of NPs up to a few monolayers.19
The variation in the area of elemental characteristic peak can
express the changes in the quantity of the corresponding
element on NPs surface.20-22 In Fig.2, the consistence between
HS-LEISS and XPS results is observed in the variation trend of
characteristic elemental peak’s area. 3Pt/C and 3Ru/C possess
larger characteristic peak areas (for the corresponding metal)
than other bimetallic samples’. As the proportion of second
metal component in loading increases, there is an interactive
variation behaviour observed between such two elements’
characteristic peak areas (in both HS-LEISS and XPS). From
3Pt/C to 1.5Pt1.5Ru/C, Pt characteristic peak area decreases
gradually accompanied with the increase of Ru peak area.
Contrarily, from 3Ru/C to 1.5Pt1.5Ru/C, Pt peak area increases
gradually with the decrease of Ru peak area. Results indicate
that these seven samples possess the seven different surface
element concentration ratios of Pt to Ru respectively. Variation
trend in the metal component’s characteristic peak area
among these seven samples is consistent with that in the
corresponding metal component’s loading detected by ICP
Fig.1 XRD patterns, elemental line-scan and mapping results. a)
XRD patterns of catalysts with various compositions. b) Partial
enlarged view of XRD patterns. c) HAADF-STEM, elemental
line-scan and mapping analysis of 1.5Pt1.5Ru/C.
bimetallic sample becomes increasingly broader. Similarly, the
diffraction peak becomes broader than monometallic 3Ru/C as
Pt proportion in metal loading increases. Result indicates the
second metal component addition can result in the increase of
diffraction peak’s full width at half maximum (FWHM), which
is derived from the decrease of metal particle diameter. Fig.1b
shows the partial enlarged view of XRD patterns. In contrast
with Pt (111) in 3Pt/C, the position of diffraction peak in
bimetallic sample shifts to higher angle since Ru component
added. Moreover, the degree of such diffraction peak position
movement gradually increases with the proportion of Ru
component in metal loading. Comparing with Ru (101) peak,
the diffraction peak of bimetallic sample shifting to lower
angle is observed since Pt component added. Results indicate
the Pt-Ru alloy formation. Considering the different atomic
size (Pt > Ru), a certain number of Ru atoms diffuse into the Pt
lattice, which leads to a compressive strain (i.e., a contraction
of the original lattice) for the original Pt fcc structure and thus
results in diffraction peak position shifting to higher angle.16 As
the Ru proportion in metal loading increases, more Ru atoms
diffuse into the Pt lattice, which leads to the larger degree of
such peak position movement. Similarly, introduction of Pt into
Ru leading to peak position shifting to lower angle is due to Pt
atoms diffusing into the Ru lattice, resulting in a tensile strain
(Table S2†), illustrating the trend of variation in bulk phase
composition is consistent with that in surface composition.
Catalytic performance in acetone hydrogenation
substantially depends on the alloy’s composition. A volcano
type variation behaviour with increased loading ratio of Pt to
Ru was observed in catalytic activity (see Table 1). With the
optimum alloy composition (i.e., 1.5Pt1.5Ru/C), both catalytic
conversion and TOF could reach their maximum values.
Significantly, variation tendency of catalytic activity observed
in acetone hydrogenation is exactly the same as that found in
3-pentanone hydrogenation, confirming the objectivity for the
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 3 of 5
View Article Online
DOI: 10.1039/C8CC04293D
Journal Name
COMMUNICATION
Table1 Catalytic performances of carbon supported PtRu
nanoalloy catalysts with various compositions.
Acetone
Catalyst
3-pentanone
hydrogenation(a)
hydrogenation(c)
Conv.
Sel.
(%)(b)
95.80
97.58
99.71
100
100
100
100
-
TOF
Conv.
TOF
(s-1)(d)
1.76
3.83
4.91
6.57
2.96
1.74
0.95
-
(%)
6.22
37.40
70.34
100
86.61
56.01
24.26
0
(s-1)(d)
9.35
23.53
37.19
46.39
28.23
16.58
5.62
-
(%)
5.61
27.40
48.92
77.62
48.59
35.01
19.35
0
3Pt/C
2.5Pt0.5Ru/C
2Pt1Ru/C
1.5Pt1.5Ru/C
1Pt2Ru/C
0.5Pt2.5Ru/C
3Ru/C
C
catalyst-free
0
-
-
0
-
a
The reaction pathways are shown in Scheme S1†. Reaction
o
conditions: T=28 C, P(H2)=5.3 MPa, 100 mg catalyst, 10 ml
b
acetone, reaction time=6 min, agitation speed=500 rpm.
Selectivity to isopropyl alcohol, by-products are diisopropyl
ether and water. c Reaction conditions: T=50 oC, P(H2)=5.3 MPa,
100 mg catalyst, 10 ml 3-pentanone, reaction time=20 min
agitation speed=500 rpm. The main product is 3-pentanol (100%
d
selectivity), no by-product was detected. Conversion was
maintained below 15%, the related conversion values and
experimental details for TOF calculations are shown in Fig.S4†.
Effect of agitation speed and catalyst’s amount on catalytic
activity are shown in Figs.S5-S6†. Results of reactions at
different time on stream are shown in Fig.S7†.
due to the higher heat of adsorption of H2 than Ru.19 Ru
possesses more affinity toward carbonyl due to Ru is more
oxophilic than Pt.19,26 The coverage of the two adsorbates on
Pt surface is different from that on Ru surface, thus resulting in
their different catalytic reaction rates. Variation in the atomic
scale distribution of Pt and Ru sites could lead to the coverage
changes of such two adsorbates. A proper surface composition
(i.e., 1.5Pt1.5Ru/C), could lead to an optimal coverage
between such two kinds of substrates adsorbed on surface and
bring the maximum activity. Higher or lower surface sites ratio
of Pt to Ru may break the optimal multiple sites status and
lead to the activity decrease.
Fig.2 HS-LEISS, XPS results and catalyst structure illustrations.
(a) 3Ru/C, (b) 2.5Ru0.5Pt/C, (c) 2Ru1Pt/C, (d) 1.5Pt1.5Ru/C, (e)
1Ru2Pt/C, (f) 0.5Ru2.5Pt/C and (g) 3Pt/C.
important role of alloy composition in catalytic ketone’s
carbonyl hydrogenation. For the catalytic selectivity in acetone
hydrogenation, Introduction of Ru into Pt could increase the
selectivity to isopropyl alcohol and that kept increasing as the
proportion of Ru in metal loading increased. 1.5Pt1.5Ru/C
exhibited 100% selectivity to isopropyl alcohol, further
increase of Ru proportion could not change the 100%
selectivity to isopropyl alcohol, indicating the diisopropyl ether
generation can be restricted when catalyst possesses more Ru
than Pt (proportion in metal loading).
Highly unsaturated surface Pt defect sites are responsible
for the diisopropyl ether generation.27 Catalytic selectivity to
diisopropyl ether decreased with the proportion of Pt in metal
loading (evaluation results). The decrease of Pt proportion in
metal loading leads to the decrease of whole surface Pt
concentration (HS-LEISS and XPS), consequently resulting in
the decrease of surface concentration of Pt atoms located at
the highly unsaturated defect sites (i.e., vertex and edge) and
thus restricting the by-product’s generation. When catalyst
possesses more Ru than Pt (proportion in metal loading), the
resultant 100% selectivity to isopropyl alcohol is attributed to
the concentration of such by-product generation site is nearly
negligible.
Alloy formation lets such two sites be uniformly mixed and
present on the surface. Alloy sites usually show two features in
the ensemble effect for the improvement of performance: 1.
synergetic behaviour; 2. complementary advantages.4 Since Pt
and Ru all possess the capability to activate such two reactants
(i.e., hydrogen and ketone),23-24 rather than an absolute
synergetic behaviour (hydrogen and ketone could be activated
simultaneously and separately by different metals), the alloy
showing higher activity tends to be attributed to the
complementary advantages between Pt and Ru on activating
the reactants. Catalytic ketone hydrogenation accords with
Langmuir-Hinshelwood mechanism that the reaction rate is
determined by the coverage of the two substrates on catalyst’s
surface.23,25 Comparing with Ru, Pt has more affinity toward H2
Metal particle sizes and metal loadings for the spent
catalysts after acetone/3-pentanone hydrogenation reactions
are shown in Fig.S8† and Table S3† respectively. Slight metal
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 4 of 5
View Article Online
DOI: 10.1039/C8CC04293D
COMMUNICATION
Journal Name
9
M. Sankar, N. Dimitratos, P. J. Miedziak, P. P. Wells, C. J. Kiely
and G. J. Hutchings, Chem. Soc. Rev., 2012, 41, 8099-8139.
leaching was observed in the spent catalyst after the
hydrogenation reaction. No evident difference was found in
NPs size for the spent catalyst compared with fresh one.
Valence states of fresh and spent catalysts (before/after
hydrogenation reaction) were determined by XPS. There is no
obvious change observed in valence distribution for spent
catalyst in contrast to the fresh one. It is known that the
presence of surface Ru4+ species facilitates the carbonyl
activation.16,23 Thus, to confirm the possible positive role of
such Ru4+ species, we performed the reduction treatment for
the fresh catalyst to remove it (Figs.S9-S10†), as a result, the
decrease of catalytic activity was observed after the catalyst’s
reduction treatment (Fig.S11†). The decreased activity when
Ru4+ is absent is due to its role of Lewis acid sites that are able
to interact with the oxygen atom of the carbonyl bond
(polarization of carbonyl),23 in the case of its presence,
improvement of hydrogenation rate would be favoured.
In conclusion, carbon supported PtRu nanoalloy catalysts
with seven different surface compositions were synthesised
and evaluated in hydrogenation of acetone. The observed
strong dependence of catalytic performance on surface
composition originates from the different catalytic properties
between the two metals and their complementary advantages
in catalysis. Similar catalysis behavior found in 3-pentanone
hydrogenation verifies the objectivity of the structure-property
relationship revealed in this study (I.e., the composition
effect), which could assist the rational design of catalyst used
in many other carbonyl compounds hydrogenation reactions
(e.g., cellulose biomass, glucose, aldehydes, carboxylic acid,
esters, etc.).
10 C. Wang, M. Chi, G. Wang, D. van der Vliet, D. Li, K. More, H.
H. Wang, A. Schlueter John, M. Markovic Nenad and R.
Stamenkovic Vojislav, Adv. Funct. Mater., 2010, 21, 147-152.
11 H.-L. Jiang and Q. Xu, J. Mater. Chem., 2011, 21, 13705-
13725.
12 Y.-J. Wang, N. Zhao, B. Fang, H. Li, X. T. Bi and H. Wang,
Chem. Rev., 2015, 115, 3433-3467.
13 S. Özkar and R. G. Finke, J. Am. Chem. Soc., 2005, 127, 4800-
4808.
14 L. S. Ott, S. Campbell, K. R. Seddon and R. G. Finke, Inorg.
Chem., 2007, 46, 10335-10344.
15 A. Balouch, A. Ali Umar, A. A. Shah, M. Mat Salleh and M.
Oyama, ACS Appl. Mater. & Interfaces, 2013, 5, 9843-9849.
16 J. Teddy, A. Falqui, A. Corrias, D. Carta, P. Lecante, I. Gerber
and P. Serp, J. Catal., 2011, 278, 59-70.
17 Y. Wang, J.-M. Zheng, K. Fan and W.-L. Dai, Green Chem.,
2011, 13, 1644-1647.
18 C. L. Bracey, P. R. Ellis and G. J. Hutchings, Chem. Soc. Rev.,
2009, 38, 2231-2243.
19 7. B.-J. Hwang, L. S. Sarma, G.-R. Wang, C.-H. Chen, D.-G.
Liu, H.-S. Sheu and J.-F. Lee, Chem.-Eur. J., 2007, 13, 6255-
6264.
20 Q. Zhai, S. Xie, W. Fan, Q. Zhang, Y. Wang, W. Deng and Y.
Wang, Angew. Chem., Int. Ed., 2013, 52, 5776-5779.
21 H. Zhang, Z. Zheng, C. Ma, J. Zheng, N. Zhang, Y. Li and B. H.
Chen, ChemCatChem, 2015, 7, 245-249.
22 L. Zhu, Y. Jiang, J. Zheng, N. Zhang, C. Yu, Y. Li, C.-W. Pao, J.-L.
Chen, C. Jin, J.-F. Lee, C.-J. Zhong and B. H. Chen, Small, 2015,
11, 4385-4393.
23 Z. Yang, D. Li, L. Zhang, J. Zheng, N. Zhang and B. H. Chen,
ChemCatChem, 2017, 9, 338-346.
24 R. Alcalá, J. Greeley, M. Mavrikakis and J. A. Dumesic, J.
Chem. Phys., 2002, 116, 8973-8980.
25 J. Pardillos-Guindet, S. Metais, S. Vidal, J. Court and P.
Fouilloux, Appl. Catal., A, 1995, 132, 61-75.
26 M. De bruyn, S. Coman, R. Bota, V. I. Parvulescu, D. E. De Vos
and P. A. Jacobs, Angew. Chem., Int. Ed., 2003, 42, 5333-
5336.
Acknowledgements
The authors acknowledge financial support from the National
Key Technology Support Program of China (No.2014BAC10B01)
and National Natural Science Foundation of China
(No.21576228 and No.21673187).
27 Z. Yang, W. Chen, J. Zheng, Z. Yang, N. Zhang, C.-J. Zhong and
B. H. Chen, J. Catal., 2018, 363, 52-62.
Notes and references
1
E. Gomez, S. Kattel, B. Yan, S. Yao, P. Liu and J. G. Chen, Nat.
Commun., 2018, , 1398.
9
2
J. P. Bosco, M. P. Humbert and J. G. Chen, Design of
Heterogeneous Catalysts: From Model Surfaces to Supported
Catalysts, Wiley, 2009.
3
4
5
J.-H. Zhong, X. Jin, L. Meng, X. Wang, H.-S. Su, Z.-L. Yang, C. T.
Williams and B. Ren, Nat. Nanotechnol., 2016, 12, 132.
J. Zheng, H. Lin, Y.-n. Wang, X. Zheng, X. Duan and Y. Yuan, J.
Catal., 2013, 297, 110-118.
G. Kyriakou, M. B. Boucher, A. D. Jewell, E. A. Lewis, T. J.
Lawton, A. E. Baber, H. L. Tierney, M. Flytzani-
Stephanopoulos and E. C. H. Sykes, Science, 2012, 335, 1209.
M. M.-J. Li, L. Ye, J. Zheng, H. Fang, A. Kroner, Y. Yuan and S.
C. E. Tsang, Chem. Commun., 2016, 52, 2569-2572.
Y. Nakagawa, K. Takada, M. Tamura and K. Tomishige, ACS
6
7
8
Catal., 2014,
R. Zheng, M. P. Humbert, Y. Zhu and J. G. Chen, Catal. Sci.
Technol., 2011, , 638-643.
4, 2718-2726.
1
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 5
ChemComm
Ultra efficient and green catalysis for acetone hydrogenation: boosting the catalytic
performance by adjusting the nanoalloy surface composition.