Synthesis of biomass-derived methylcyclopentane as a gasoline additive via aldol condensation/hydrodeoxygenation of 2,5-hexanedione

Article abstract of DOI:10.1039/c4gc02292k

A novel approach to produce biomass-derived gasoline is the hydrolysis of 2,5-dimethylfuran (DMF) to produce 2,5-hexanedione followed by base-catalyzed intramolecular aldol condensation of this product to form 3-methylcyclopent-2-enone (MCP). By proper choice of catalysts and conditions, MCP yields of 98% can be achieved. We further show that hydrogenation of MCP over Pt/NbOPO₄ gives methylcyclopentane with virtually quantitative yields. Methylcyclopentane is an attractive gasoline substitute for ethanol, since its octane number is similar to ethanol and its gravimetric energy density is 58% higher. This journal is

Full text of DOI:10.1039/c4gc02292k

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Synthesis of Biomass-Derived Methylcyclopentane as a Gasoline Additive via
Aldol Condensation/Hydrodeoxygenation of 2,5-hexanedione
Eric R. Sacia, Matthew H. Deaner, Ying “Lin”Louie, and Alexis T. Bell*
Department of Chemical and Biomolecular Engineering
University of California, Berkeley
1
07 Gilman Hall
Berkeley, CA 94720, USA
Corresponding Author Phone: 1-(510) 642-1536
Submitted to:
Green Chemistry
*
Author to whom correspondence is addressed: bell@cchem.berkeley.edu

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Table of Contents Entry
Highlights: We demonstrate that 2,5-hexanedione, a biomass-derived molecule, can be
converted selectively in two steps to methylcyclopentane, an exceptional gasoline additive.

Page 3 of 24
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Abstract
A novel approach to produce biomass-derived gasoline is the hydrolysis of 2,5-
dimethylfuran (DMF) to produce 2,5-hexanedione followed by base-catalyzed intramolecular
aldol condensation of this product to form 3-methylcyclopent-2-enone (MCP). By proper choice
of catalysts and conditions, MCP yields of 98% can be achieved. We show further that
hydrogenation of MCP over Pt/NbOPO gives methylcyclopentane with virtually quantitative
4
yields. Methylcyclopentane is an attractive gasoline substitute for ethanol, since its octane
number is comparable to ethanol and its gravimetric energy density is 58% higher.

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Increasing concern with the environmental effects of greenhouse gases emissions
resulting from the combustion of fossil fuels has motivated the search for strategies by which
1
-3
biomass could be converted to transportation fuels in a sustainable manner. First generation
biofuels produced from sugars, starches and triglycerides offer a temporary solution but face
4
significant limitations because they use a limited portion of the total biomass, produce
5
oxygenated fuels that are not fully compatible with the current infrastructure, and can result in
6
the use of land that would otherwise be used to produce food. Ethanol derived from corn or
sugarcane has been used to provide a biomass-derived component that can be blended into
gasoline. However, the low energy density of this fuel, together with its limited blending level
(<10%) motivate the search for alternative biomass-based fuels. Lignocellulosic biomass derived
from non-edible sources of biomass offers an attractive alternative to using starch or sucrose.
7
The carbohydrate portion of lignocellulosic biomass can be converted to sugars that, in turn, can
2
, 8-12
be transformed into a variety of platform molecules for the production of fuels or chemicals.
A prominent example of a platform molecule is 5-hydroxymethylfurfural (HMF), which
2
, 12-13
can be produced via dehydration of glucose, fructose or sucrose.
HMF can be reduced to
1
4
2
,5-bis(hydroxymethyl)furan, which, following hydrogenolysis (76-79% yield) or formic acid-
1
5
assisted deoxygenation (>95% yield), produces 2,5-dimethylfuran (DMF). DMF has been
suggested as a fuel additive due to its high octane number; however, recent work indicates that
1
6
its use may be limited by its moderate toxicity. While DMF could be converted to n-hexane by
complete hydrodeoxygenation (Figure 1), this product is not attractive because of its low
1
7
blending octane number, 21. On the other hand, DMF will readily undergo quantitative
1
8
hydrothermal hydrolysis to 2,5-hexanedione (HD), as shown in Figure 1.

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We describe here a previously unreported pathway for producing a gasoline additive from
HD that involves base-catalyzed, intramolecular aldol condensation of HD to produce 3-
methylcyclopent-2-enone (MCP) as an intermediate. Partial hydrogenation of MCP to 3-
methylcylopentanol produces a material with volatility well within the range of gasoline.
Additionally, complete hydrodeoxygenation of MCP produces methylcyclopentane, which has a
17
19
blending octane number of 103 and an energy density of 46.8 MJ/kg (vs. 29.7 MJ/kg for
2
0
ethanol). Therefore, the goal of this work is to develop a method to use HD as a biomass-
derived platform molecule for the production of gasoline-range products with high selectivity
using heterogeneous catalysts. Previous studies have shown that moderate yields of MCP can be
2
1-25
achieved using soluble bases (e.g., NaOH and KOH);
however, these materials are corrosive
and difficult to recover. Therefore, it is desirable to identify solid bases suitable for catalyzing
the production of MCP from HD.
The aldol condensation of HD in toluene was investigated using a variety of solid bases;
a summary of these efforts is shown in Table 1. The source of the catalysts and their methods of
activation are discussed in the Supporting Information. K PO (entry 1), a mild base with high
3
4
2
6
selectivity for aldol condensation reactions, exhibited high selectivity to MCP but low activity,
most likely due to its low surface area (Supporting Information). Anatase TiO (entry 2) was
2
more active in catalyzing the cyclization of HD, but was less selective than any of the other
catalysts screened. Basic Al O (entry 3) produced a higher yield of MCP than TiO but also a
2
3
2
moderate amount of oligomers. Magnesium oxide and MgO doped with modifiers such as Al and
Zr were examined based on previous reports of the activity of such materials for base-catalyzed
2
7-28
condensations.
As noted in Table 1, entries 4-6, these materials enabled attainment of HD
conversions of 89-99% and MCP selectivities of 78-93%. Additional products observed in all

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cases were higher oligomers formed by the reaction of MCP with either another equivalent of
MCP or HD. Additional base-catalyzed condensations conducted in other solvents are presented
in the Supporting Information with limited success.
To suppress the oligomerization of MCP, we investigated the possibility of using a bi-
phasic system, as shown in Figure 2. In this case, HD is preferentially dissolved in water and the
less polar MCP is preferentially extracted into an organic solvent. From here, MCP can either be
29-31
separated and sold directly for specialty chemicals applications,
or further hydrogenated to
produce fuels. Toluene was employed as the extracting solvent because the partition coefficient
of MCP in toluene is significantly higher than that in alkanes. Morevoer, HD also has a lower
solubility in toluene compared to MCP (see Supporting Information). Entries 7-15 of Table 1
report our findings for MCP condensation in the biphasic system. NaOH (0.2 M) was also
investigated in addition to the catalysts considered previously.
While NaOH and K PO (Table 1, entries 7 and 8) resulted in 100% conversion of HD in
3
4
0
.75 h and high yields of MCP, these catalysts were not considered further because they fully
dissolve in the aqueous phase. In contrast to what was observed in toluene alone, TiO , basic
2
Al O , MgO, and Mg-Zr-O showed very low activity when the catalysts were exposed to water
2
3
at 180°C, indicative of inhibition of these catalyst by water. While Mg-Zr-O has been reported to
3
2-33
be active and water stable at mild conditions in other reactions,
it did not prove to be suitable
for the present work because of its low activity in forming 3-methylcyclopent-2-enone in the bi-
phasic system. For identical reaction conditions, the conversion of HD over Mg-Al-O in the
biphasic system was roughly half of that observed for the reaction carried out in the monophasic
system (compare entries 13 and 6). Here again, the lower activity of Mg-Al-O in water compared
to toluene is attributed to the inhibiting effect of adsorbed water and associated structural

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changes. This effect, though, can be overcome by increasing the time of reaction from 0.75 h to 2
h and further increased by raising the amount of catalyst used to 50 mg (see Table 1, entries 14
and 15). It is particularly notable that, in the bi-phasic system, virtually all of the converted HD
goes to MCP.
The temporal changes in the compositions of HD and MCP are shown in Figure 3 for the
reaction of HD in toluene and in a water-toluene mixture with Mg-Al-O as the catalyst. When
the reaction was carried out in toluene, 99% of HD was converted within the first 20 min of
reaction, whereas the yield of MCP rose to a maximum value of 85%. For longer reaction times,
the yield of MCP slowly declined. This loss in MCP is predominantly attributable to the reaction
of HD and MCP with MCP to form oligomers (see Figure 1 and Supporting Information). In the
biphasic system, the conversion of HD is over eight times slower than in the monophasic system
but results in higher yield of MCP, e.g., after 2 h of reaction, the conversion of HD is 99% and
the yield of MCP is 98%. The very high yield of MCP in the bi-phasic system is a direct
consequence of the extraction of MCP from the aqueous phase, thereby reducing the possibility
of its reaction with itself or with unreacted HD.
The stability of Mg-Al-O, calcined at 700°C for 2 h, was evaluated for both the mono-
phasic and bi-phasic systems (Supporting Information). For reaction in toluene, after five
reaction cycles the conversion of HD decreased from 99% to 25% due to a decrease in the
2
catalyst surface area from 182 to 27 m /g. After completion of the fifth cycle, ~2 mg of water
had formed per mg of catalyst, facilitating this structural change and inhibiting the activity of the
o
catalyst. However, after re-calcination for 2 h at 700 C, the initial activity was restored and the
2
surface area returned to 149 m /g. Based on this knowledge, intermediate drying steps to remove
water between cycles or a Dean-Stark apparatus for continuous water removal could also be used

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to limit deactivation. De-activation occurred much more rapidly in the bi-phasic system; much of
2
the initial activity was lost by the second cycle, and the surface area decreased to 69 m /g after
the first cycle, at which point it remained stable. While some activity could be regained by re-
calcination, the initial catalyst activity and surface area could not be fully restored in the bi-
phasic system (see Supporting Information). These results indicated that while conducting MCP
condensation in a bi-phasic system results in a high MCP yield, it leads to a loss in catalyst
recyclability. By contrast, operation in the monophasic system allows for catalyst regeneration
but results in lower MCP yields. Systematic study of the effects of water exposure to
hydrotalcite-derived Mg-Al-O materials is in progress using multiple reaction systems and will
be reported separately.
To serve as a fuel, the alkene and ketone functionalities in MCP must be removed in
order to achieve long storage stability. This can be achieved by hydrogenation. Table 2
demonstrates that the conversion of MCP and the distribution of products are strong functions of
the catalyst composition. All carbon-supported catalysts result in 100% conversion of MCP after
5
h of reaction. Pd/C produced principally 3-methylcyclopentanone (87%), whereas Pt/C, Rh/C,
and Ru/C produced over 92% 3-methylcyclopentanol. Only very small yields of
methylcyclopentane were obtained using any of the carbon-supported catalysts.
Previous studies have demonstrated that hydrodeoxygenation of biomass-derived furanics
3
4-35
and their derivatives is enabled by supporting noble metals on acidic supports.
In Table 2, we
show the results of MCP hydrogenation using Pt/C together with Amberlyst 70 (A70) or
NbOPO -supported Pt or Pd. Nearly quantitative yields of methylcyclopentane were obtained
4
using Pt/C+A70 or Pt/NbOPO at reaction temperatures of 150°C. These results suggest that the
4
3
-methylcyclopentanol produced by the hydrogenation of MCP over Pt undergoes dehydration

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over the acidic sites of A70 or NbOPO and that the resulting alkene then undergoes
4
hydrogenation over Pt to form methylcyclopentane, as shown in Table 2. Additional screening of
Pt/NbOPO is reported in the Supporting Information. The Pt/NbOPO sample used in this work
4
4
was also tested for stability, as shown in Table 2, entry 7. After three cycles, the catalyst retained
its original activity, showing that it can be recycled without a significant loss in activity. These
findings are consistent with those of earlier work, which show that niobium supports are water
3
4
stable and that Pt/NbOPO does not show apparent signs of deactivation after 38 h of time on
4
3
5
stream for the hydrodeoxygenation of C diols to octane in a THF solvent.
8
Hydrodeoxygenation of MCP over Pd/NbOPO resulted in production of only 33%
4
methylcyclopentane and formed C12 products in significant yields (46%). While some
etherification of 3-methylcyclopentanol was observed (14%), most of the observed C products
1
2
(32%) were a direct consequence of accumulation of 3-methylcyclopentanone over Pd/NbOPO4.
It is proposed that 3-methylcyclopentanone undergoes acid-catalyzed aldol condensation on
NbOPO to form C dimer condensates, which in turn undergo various degrees of hydrogenation
4
12
over Pd (see Supporting Information).
Conclusion
Base-catalyzed condensation of HD to MCP can be performed with exceptional
selectivity. While Mg-Zr-O provides the highest selectivity for transformation of HD to MCP in
a mono-phasic toluene solution, Mg-Al-O provides higher activity. The formation of water as a
byproduct of HD condensation contributes to a loss of catalyst activity, but the original activity
can be regained by recalcination of the catalyst. Alternatively, continual removal of water could
also be applied to prevent water-associated catalyst deactivation. Higher MCP selectivity could

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be achieved by conducting HD condensation in an aqueous phase and extracting the product,
MCP, into toluene. However, in this case, a significant part of the original activity of Mg-Al-O
was lost after one reaction cycle due to structural changes of the catalyst and an associated loss
in catalyst surface area which could not be regained by recalcination.
Hydrogenation of MCP to useful products could be achieved by a variety of supported
metals. Pt/C and Ru/C provide high selectivity to 3-methylcyclopentanol, a potential octane
booster for gasoline, while Pt/NbOPO4 was active and selective for formation of
methylcyclopentane, an alkane already found in gasoline. Using the two-step strategy of base-
catalyzed condensation followed by hydrogenation, high-quality gasoline additives could be
produced from biomass-derived 2,5-hexanedione in exceptional yields. The high blending octane
number, energy density, and gasoline miscibility of methylcyclopentane suggest that it would be
an excellent biomass-based gasoline blending agent.
Acknowledgements
This work was supported by the Energy Biosciences Institute. E. R. Sacia also
acknowledges support from a National Science Foundation Graduate Research Fellowship under
Grant No. DGE 1106400.

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Figure 1: Pathways of HMF and HD Utilization for Gasoline Products
Figure 2: Bi-Phasic Reactor Scheme for HD Cyclization
1
00
80
60
40
20
0
H O/Toluene
2
Toluene
HD
MCP
Oligomers
0
20
40
60
80
100
120
Time / min
Figure 3: HD cyclization reaction to MCP in toluene (hollow symbols/dashed lines) and
H O/toluene (solid symbols/lines). Reaction Conditions: 4 mL solvent (toluene or 2 mL H O/2
2
2
mL toluene), 1.2 mmol HD, 50 mg Mg-Al-O as catalyst, 180°C, 2 h.

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Table 1: Screening of Basic Catalysts for Aldol Condensation of HD to MCP
Entry Catalyst
Cat. Amt. Solvent
mg]
Time
[h]
Conv. HD Yield MCP Yield Oligomers MCP Sel.
[
[%]
35
74
94
99
89
94
100
100
2
[mol %]
31
53
78
78
82
75
85
94
1
[mol %]
[mol %]
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
K PO
40
40
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
0.75
0.75
0.75
0.75
0.75
0.75
3
89
71
84
78
93
80
85
94
-
3
4
TiO2
16
13
17
7
Basic Al O 40
2
3
MgO
40
Mg-Zr-O
Mg-Al-O
NaOH
40
40
15
15
6
0.2 M
40
H O/Toluene 0.75
2
K PO
3
H O/Toluene 0.75
2
4
TiO2
40
H O/Toluene 0.75
2
0
0
1
2
3
4
5
Basic Al O 40
H O/Toluene 0.75
2
2
1
0
-
2
3
MgO
40
40
40
40
50
H O/Toluene 0.75
3
2
0
-
2
Mg-Zr-O
Mg-Al-O
Mg-Al-O
Mg-Al-O
H O/Toluene 0.75
2
4
3
0
-
H O/Toluene 0.75
2
52
85
99
51
84
98
0
99
99
98
H O/Toluene 2.0
2
1
H O/Toluene 2.0
2
2
Reaction Conditions: 1.2 mmol HD, 4.0 mL toluene or 2.0 mL toluene/2.0 mL water, temperature: 180 °C.
Catalyst synthesis procedures and sources available in Supporting Information. Mg-Al-O –Mg/Al mixed metal
oxide from calcined hydrotalcite (Mg/Al = 3), Mg-Zr-O –Mg/Zr mixed metal oxide (synthesis in Supporting
Information).

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Table 2: Screening of Catalysts for Hydrogenation of MCP
Entry Catalyst
Conversion of Yield of
Yield of
Alcohol
[mol %]
Yield of
Alkane
[mol %]
Yield of Coupled
C Products
[mol %]
1
MCP
%]
Ketone
[mol %]
12
[
1
2
3
4
5
6
Pt/C
100
100
100
100
100
100
5
92
13
92
99
0
2
Pd/C
87
1
0
0
5
0
1
1
Rh/C
2
Ru/C
0
1
a
Pt/C + A70
1
98
99
Pt/NbOPO4
0
0
Pt/NbOPO
4
7
8
100
100
0
6
0
98
33
2
rd
(
3 cycle)
Pd/NbOPO4
13
46
Reaction Conditions: 1.2 mmol MCP, 2.0 mL toluene, 0.1 mol% exposed metal loading, 3.0 MPa H pressure, 150
2
a
°
C, 5h. 5 mol% acid sites on A70. Catalyst synthesis procedures and sources available in Supporting Information.

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Synthesis of Biomass-Derived Methylcyclopentane as a Gasoline Additive via
Aldol Condensation/Hydrodeoxygenation of 2,5-hexanedione
Eric R. Sacia, Matthew H. Deaner, Ying “Lin” Louie, and Alexis T. Bell*
Department of Chemical and Biomolecular Engineering
University of California, Berkeley
1
07 Gilman Hall
Berkeley, CA 94720, USA
*
Author to whom correspondence is addressed: bell@cchem.berkeley.edu
Supporting Information
Contents
1
2
3
4
5
6
. Experimental Methods and Materials
S2
. Supplemental Reaction Information
. Characterization of Minor Products
. Characterization of Catalysts
S4
S7
S8
. Catalyst Activity in Water with Varied Calcination Conditions
. Additional References
S10
S10

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1
1
. Experimental Methods and Materials
.1. Reactants and Catalysts
All chemicals were used as received without further purification. Starting materials,
including 2,5-hexanedione (HD, >98%) and 3-methyl-2-cyclopentenone (97%), were obtained
from Sigma Aldrich, USA. Analytical standards which were used to verify the products observed
by GC include 3-methylcyclopentanone (Alfa Aesar, 99%), 3-methylcyclopentanol (Acros,
mixture of isomers, 99%), methylcyclopentane (Aldrich, 97%), and dodecane (Aldrich, > 99%).
Solvents were purchased as HPLC grade solvents from Fisher Scientific, while nanopure water
was used for aqueous-phase experiments.
The following basic catalysts were obtained from commercial sources: K PO (Acros,
3
4
1
9
7%), TiO (Aldrich, anatase, 99.7%), and basic Al O (Fisher, Brockman Activity I). MgO and
2 2 3
2
Mg-Zr-O were synthesized according to previously reported methods. Mg-Al-O was
synthesized by calcination of synthetic hydrotalcite (Sigma Aldrich) in static air in a muffle
furnace. The temperature of the furnace was ramped at 2°C/min to 700°C, held for two hours,
and cooled to 250°C before removal from the oven and storage.
Amberlyst 70 was obtained as a sample from the Dow Chemical Company. It was dried
in vacuo at 105°C before grinding into a fine powder and sieving to ensure all particles were less
than 63 μm in diameter. The NbOPO support was obtained as a sample from CBMM, Brazil and
4
calcined in flowing air at 300°C (2°C/min) prior to use. Supported Pt/NbOPO and Pd/NbOPO
4
4
were synthesized by incipient wetness impregnation of calcined NbOPO . The respective
4
precursors, H PtCl , hexahydrate (Aldrich) and Pd(NO ) , dihydrate (Aldrich), were dissolved in
2
6
3 2
water and slowly added to the catalyst with thorough mixing. The catalysts were then reduced in
flowing H (9% in He) for 2 hours at 300°C (2°C/min) to obtain 2 wt% metal loading.
2
1
.2. Product and Catalyst Characterization
Reaction products were characterized by gas chromatography (GC) using a Varian CP-
800 GC equipped with a flame ionization detector (FID) and Varian 320-triple quadrupole mass
3
spectrometer (MS). Product components were identified by GC/MS. Separation by GC was
performed with a FactorFour VF-5 capillary column. Product mixtures were diluted such that
components of interest were present in concentrations of 0.01-1.0 mg/mL using ethyl acetate,
ethanol, or dicholoromethane as a GC solvent.
Quantification was performed using dodecane as an internal standard during reaction.
Identity of major intermediates and products were determined from commercially available
chemicals. The FID response factors of these components were determined by calibration of the
peak area of a known quantity of the analyte compared to a known quantity of dodecane at
several concentrations. Quantification of minor components, for which commercial sources were
not available, was done by the effective carbon number method using the predicted response
3
factor based on the structure of the molecule determined by GC/MS.
Catalyst surface area was measured using a Micromeritics TriStar system. Approximately
1
00 mg of the catalyst was added to a tube and degassed for six hours in flowing argon at 180°C.
The surface area was then assessed using the BET isotherm. Mean metal particle size on
supported metal catalysts was measured using a Micromeritics AutoChem II Chemisorption
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Analyzer to perform CO pulse chemisorption. Approximately 125 mg of catalyst was added to
the sample tube, and the samples were reduced at 250°C in flowing H (10% in Ar). After 30
2
minutes at 250°C, the sample was cooled to 40°C and subjected to pulses of CO in He. CO
uptake was measured by a TCD. Structure of solid catalysts was assessed using x-ray diffraction
patterns on a Bruker D8 instrument. Measurements were taken over a 2θ range of 10-80 degrees
with a 0.02 degree step size.
1
.3. Experimental Conditions
In a typical base-catalyzed experiment, the catalyst (40-50 mg) was weighed out and
added to a 12 mL Q-tube reactor from Q Labtech. The starting materials were then introduced as
mixture of toluene (2 mL), HD (1.2 mmol), and dodecane (136 mg). Water or additional toluene
was added as required. A Teflon-coated magnetic stir bar was then added and the reactor was
sealed with a PTFE seal. The sealed reactor was introduced to a preheated silicone oil bath on an
IKA stir plate equipped with an ETS-D5 thermocontroller and stirred at 500 RPM for the
prescribed reaction time, after which the reactor was removed and cooled. The product mixture
was then diluted as described previously and analyzed by GC.
Hydrogenation testing was performed using an HEL ChemSCAN system that contained
eight parallel autoclave reactors with independent temperature and pressure control. The catalyst
(0.1 mol% exposed metal with respect to MCP) was added to the autoclave along with the
reaction solution (2 mL toluene, 1.2 mmol MCP, 1.14 mg dodecane). The autoclave was then
sealed, flushed with N and H (2.0 MPa × 2), and reacted for five hours with 500 RPM stirring
2
2
and 3.0 MPa H Pressure. After cooling in an ice bath, the reactors were opened, and the material
2
was transferred to a 15 mL centrifuge tube. Transfer of the material was completed with 5
washes of 2 mL of dichloromethane. The product mixture was then diluted as described
previously and analyzed by GC.
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2
2
. Supplemental Reaction Information
.1. Measurement of Partition Coefficient
Procedure: Approximately 20.0 mg of MCP, HD, and dodecane were added to a bi-phasic
system containing 2.0 mL of nanopure water and 2.0 mL of organic. A stirbar was added and the
mixture was allowed to stir and equilibrate for a period of 30 minutes at 25.0°C on the surface of
an IKA stir plate. The temperature was controlled via an IKA ETS-D5 thermocontroller. After 30
minutes, 50 μL of sample was removed from the organic phase. The organic layer was then
analyzed by GC in 1.0 mL of ethyl acetate as a GC solvent. The total mass balance was assured
by also taking a sample of both phases, combining and diluting them with ethanol, and analyzing
the total amount of materials by GC.
Measurement of the partition coefficient using toluene as a bi-phasic extractant was also
completed at 180°C by creating a mixture at the same concentrations to those listed above, but
with 12 mL of each phase instead of 2.0 mL. The 24 mL mixture was loaded into a 50 mL Parr
reactor and heated to 180°C with constant stirring. The toluene phase was sampled at 180°C
using a dip tube. The combined mass balance was assured after cooling the mixture and sampling
both phases, as described previously.
Table S1: Partition Coefficient of HD and MCP in the Organic Phase
Temp
Percent HD
in
Percent MCP
in
MCP Part.
Coeff.
HD Part.
Solvent
(°C)
Organic (%)
Organic (%)
Coeff. (PHD
)
(PMCP
)
PMCP/PHD
Butanol
25
56.4
96.2
64.9
3.3
74.5
99.5
71.8
8.7
1.29
25.10
1.85
2.92
2.26
CHCl3
Ethyl Acetate
Hexanes
25
25
25
>50
2.54
0.10
>2
1.38
2.80
0.03
Trimethyl
Acetonitrile
2
5
58.7
67.3
1.42
2.06
1.45
Toluene
Toluene
25
37.3
44.0
55.4
66.0
0.59
0.79
1.24
1.94
2.09
2.47
180
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2
.2. Catalyst Recyclability Data
Procedure: The reaction was performed as described in the manuscript. At the end of reaction,
the Q-Tube reactor was centrifuged at 2000 RPM for ten minutes, and the supernatant was
decanted and analyzed as normal. The remaining catalyst was resuspended and washed with
toluene (4 mL) for mono-phasic reactions or water (4 mL) for bi-phasic reactions. The mixture
was then recentrifuged and decanted again. This washing procedure was repeated one additional
time. The starting material was then loaded again for the following cycle. After five cycles, the
catalyst was separated and re-calcined for two hours at 700°C (2°C/min ramp rate). The material
was then subjected to an additional cycle, as shown in Figure S1.
1
00
100
80
60
40
20
0
a)
b)
80
60
40
20
0
1
2
3
4
5
6
1
2
3
4
5
6
Re-calcined
Re-calcined
Cycle
Cycle
MCP
MCP
Oligomers
Oligomers
HD Conv.
HD Conv.
Figure S1: Recyclability of HD cyclization reaction to MCP (a) in toluene and (b) H O/toluene
2
using Mg-Al-O. Reaction Conditions: 4 mL solvent (toluene or 2 mL H O/2 mL toluene), 1.2
2
mmol HD, 40 mg Mg-Al-O, 180°C, 1.5 h. Mg-Al-O was removed and re-calcined after 5 cycles.
th
A 6 cycle was then run on this re-calcined material.
The stability of the hydrogenation catalyst, Pt/NbOPO (2 wt%) was also tested under
4
hydrogenation conditions. After three reaction cycles, the catalyst remained stable, achieving a
methylcyclopentane yield of 98% and a yield of C products of 2%. This is nearly identical to
12
the results observed in entry 6 of Table 2 in the main manuscript, indicating the catalyst does not
deactivate rapidly.
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2
.3. Reactions in varied solvent systems
Table S2: Reaction of HD to MCP in various solvents catalyzed by K PO4
3
Temp
°C)
Time
(hr)
K PO Loading
HD Conv.
(%)
MCP Yield
(mol%)
3
4
Entry
Solvent
(
(mol%)
1
2
3
4
5
6
7
8
Toluene
100
100
100
100
100
100
180
180
4
4
2
4
4
2
2
2
97%
97%
97%
97%
97%
97%
2.0%
6.0%
39.8
27.6
98.3
37.1
61.8
99.9
91.4
98.4
11.8
10.8
33.5
5.4
Trimethyl
Acetonitrile
Dimethyl
Formamide
Propyl Acetate
Dioxane
25.2
64.4
82.5
95.2
Water
Water
Water/Toluene
Reaction Conditions: 3.4 mmol HD, 5.8 mL solvent, temperature: 100-180 °C. Catalyst loading is total K PO
3
4
with respect to HD.
2
.4. Hydrogenation Screening
Table S3: Hydrodeoxygenation Screening with Pt/NbOPO4
MCP
Conv.
Ketone
Yield
(mol%)
C12
Products
(mol%)
Pt Loading Temp
Alcohol Yield Methylcyclopentane
Entry
(
mol%)
(°C)
170
150
110
110
110
90
(%)
Yield (mol%)
(
%)
1
2
3
4
5
6
0.1 mol%
0.1 mol%
0.05 mol%
0.1 mol%
0.2 mol%
0.1 mol%
100
100
100
100
100
100
0
0
0
0
0
0
0
96
98
20
32
44
28
4
2
0
68
54
41
64
11
14
15
7
Reaction Conditions: 1.2 mmol MCP, 2.0 mL toluene, 0.05-0.2 mol% exposed metal loading, 3.0 MPa H2
pressure, 5h. Majority of C12 products are ether products at < 110°C and are C-C bonded dimers at > 150°C.
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3
. Characterization of Minor Products
Dodecane
Internal Standard)
1.0
0.8
0.6
0.4
0.2
0.0
(
MCP/MCP
Oligomer
MCP/HD
Oligomer
C H O
6
8
C H O
12 14
C H O
2
1
2
16
MW: 174
MW: 192
10
11
12
13
14
15
16
17
18
19
20
21
22
Time / min
Figure S2: Products of mono-phasic HD cyclization to MCP.
0.20
0.15
0.10
0.05
0.00
Dodecane
(
Internal Standard)
C H O
1
2
22
MW: 182
C H O
12
20
MW: 180
C H
22
12
C H O
MW: 166
12 22
MW: 182
17
18
19
20
21
22
Time / min
Figure S3: Products of MCP hydrodeoxygenation using Pd/NbOPO (showing oligomer
4
condensates). Plausible structures of hydrogenated oligomers are shown based on mass spectra
signatures.
Note: All significant product peaks using Pt/C, Pd/C, or Pt/NbOPO were verified with
4
commercially available reference samples and MS.
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4
4
. Characterization of Catalysts
.1. Characterization of Catalyst Surface Area
Table S4: Characterization of catalyst surface area via BET analysis.
Entry
Catalyst
Catalyst Cycle
BET Surface
2
-1
Area [m g ]
1
K
3
PO
4
0
0.15
2
3
4
5
6
7
8
9
TiO
2
0
118
148
182
77.2
178
67.6
27.5
70.0
148
Basic Al
MgO
O
2 3
0
0
Mg-Zr-O
Mg-Al-O
Mg-Al-O
Mg-Al-O
Mg-Al-O
Mg-Al-O
0
0
5 (bi-phasic)
5 (mono-phasic)
5 (bi-phasic) – Re-calcined
5 (mono-phasic) – Re-calcined
10
4
.2. Characterization of Metal Dispersion and Particle Size
Table S5: Metal dispersion and particle size determined by CO pulse chemisorption.
Sample
Dispersion
%]
Particle Size [nm]
[
Pt/C
25
21
4.6
5.4
Pd/C
Ru/C
Rh/C
20
24
13
35
5.0
4.5
8.4
3.2
Pt/NbOPO
4
Pd/NbOPO
4
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4
.3. XRD of Optimal Catalyst Materials
Figure S4: XRD powder patterns of Sigma Aldrich hydrotalcite and Mg-Al-O (calcined
hydrotalcite), showing the transition from the brucite-like hydrotalcite to the periclase Mg-Al-O.
Figure S5: XRD powder patterns of calcined NbOPO before and after impregnation of Pt
4
(post-reduction).
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5
. Catalyst Activity in Water with Varied Calcination Conditions
Figure S6: HD conversion (● and ○) in a water/toluene bi-phasic system as a function of Mg-
Al-O calcination temperature using a 1 hour holding period (●) and 2 hour holding period (○)
Reaction Conditions: 2 mL toluene, 2 mL H O, 1.2 mmol HD, 20 mg Mg-Al-O, 180°C, 1.5 h.
2
Table S6: Characterization of Mg-Al-O surface area vs. calcination severity.
Entry
Catalyst
Calcination Temp
°C)
Holding Period BET Surface
2
-1
(
(h)
Area [m g ]
1
Mg-Al-O
450
1
190
2
3
4
5
6
7
Mg-Al-O
Mg-Al-O
Mg-Al-O
Mg-Al-O
Mg-Al-O
Mg-Al-O
500
550
600
650
700
700
1
1
1
1
1
2
236
237
224
218
205
182
6
. Additional References
1
. J. K. Bartley, C. Xu, R. Lloyd, D. I. Enache, D. W. Knight and G. J. Hutchings, Appl. Catal.
B-Environ., 2012, 128, 31-38.
2
3
. ꢀꢁ aꢁ ꢂꢁ ꢂramendꢃaꢅ ꢆꢁ ꢇorꢈuꢅ ꢉꢁ ꢊimꢋneꢌꢅ ꢂꢁ ꢀarinasꢅ ꢊꢁ ꢀꢁ ꢀarinasꢅ ꢊꢁ ꢂꢁ ꢍavꢃo, J. R.
Ruiz and F. J. Urbano, Colloids Surf. Physicochem. Eng. Aspects, 2004, 234, 17-25.
. A. D. Jorgensen, K. C. Picel and V. C. Stamoudis, Anal. Chem., 1990, 62, 683-689.
ꢄ
ꢄ
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