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Chemical Science
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confirmed by the IR spectra of the ex situ Cu-Ga/SiO2 sample
References
DOI: 10.1039/D0SC00465K
1
after reacting with H2/13CO2 (Figure S24) showing the 13C-H
1.
G. A. Olah, A. Goeppert, Surya Prakash, G. K. , Beyond Oil
and Gas: The Methanol Economy, 2nd ed., Wiley-VCH:
Weinheim, Germany, 2011.
stretches at around 2954 and 2855 cm-1 indicating the presence
of methoxy, while no band associated with formate species are
observed. While formate species are also likely formed as
reaction intermediates on Cu-Ga/SiO2 under reaction
condition, the lower stability of formate compared to methoxy
would be consistent (and explains) the higher CH3OH selectivity
of this material in contrasts to other systems. Indeed, stable
formate species have been shown to be able to generate methyl
formate that readily decomposes into CO.6 Further work is
needed to investigate the formation (or not) of formate species
as key intermediate in this Cu-Ga/SiO2 system.
2.
A. Goeppert, M. Czaun, J.-P. Jones, G. K. Surya Prakash and
G. A. Olah, Chem. Soc. Rev., 2014, 43, 7995-8048.
A. Olah George, Angew. Chem., Int. Ed., 2012, 52, 104-107.
J. Artz, T. E. Müller, K. Thenert, J. Kleinekorte, R. Meys, A.
Sternberg, A. Bardow and W. Leitner, Chem. Rev., 2018,
118, 434-504.
3.
4.
5.
6.
A. Álvarez, A. Bansode, A. Urakawa, A. V. Bavykina, T. A.
Wezendonk, M. Makkee, J. Gascon and F. Kapteijn, Chem.
Rev., 2017, 117, 9804-9838.
E. Lam, J. J. Corral-Pérez, K. Larmier, G. Noh, P. Wolf, A.
Comas-Vives, A. Urakawa and C. Copéret, Angew. Chem.,
Int. Ed., 2019, 58, 13989-13996.
Conclusions
7.
8.
9.
A. Y. Rozovskii and G. I. Lin, Top. Catal., 2003, 22, 137-150.
K. T. Jung and A. T. Bell, Catal. Lett., 2002, 80, 63-68.
A. Baiker, M. Kilo, M. Maciejewski, S. Menzi and A.
Wokaun, Stud. Surf. Sci. Catal., 1993, 75, 1257-1272.
M. Behrens, F. Studt, I. Kasatkin, S. Kühl, M. Hävecker, F.
Abild-Pedersen, S. Zander, F. Girgsdies, P. Kurr, B.-L. Kniep,
M. Tovar, R. W. Fischer, J. K. Nørskov and R. Schlögl,
Science, 2012, 336, 893-897.
The use of SOMC was explored in order to understand the
promotional effect of gallium in Cu-based CO2 hydrogenation
catalysts, starting from well-defined silica-supported GaIII sites
as an initial support. This approach generates small and
narrowly distributed silica-supported CuGax nanoparticles along
with residual GaIII Lewis acidic sites. This is in contrast to
previously studied well-defined isolated ZrIV and TiIV sites that
yields Cu nanoparticles surrounded with isolated metal
10.
11.
J. Schumann, T. Lunkenbein, A. Tarasov, N. Thomas, R.
Schlögl and M. Behrens, ChemCatChem, 2014, 6, 2889-
2897.
35
interfacial sites.34, These materials are readily oxidized to
generate the corresponding CuO and GaIII sites upon exposure
to air, but can be partially reduced back to CuGax alloys under
H2. These CuGax systems display improved catalytic
performances in the hydrogenation of CO2, allowing the
increase in the overall CH3OH (CH3OH + DME) selectivity (up to
ca. 90%) at higher conversion (3%) by comparison with the
benchmark catalyst, Cu-Zr/SiO2 and Cu-Ti/SiO2. Under reaction
conditions, the silica-supported CuGax de-alloys yielding Cu
nanoparticles and GaIII sites indicating that the increased
activity and selectivity is likely due to an increased interfacial
area between Cu0 and GaIIIOx that would promote CH3OH
formation. In fact, methoxy surface species are the only
observed intermediates according to ex situ solid state NMR or
IR. This study overall shows the subtle difference between
promoters; it opens new ways to tailor CH3OH selective
catalysts. We are currently exploring other promoters to
understand their role and to design improved CO2
hydrogenation catalysts via a more rational design.
12.
13.
14.
15.
16.
17.
J. D. Grunwaldt, A. M. Molenbroek, N. Y. Topsøe, H. Topsøe
and B. S. Clausen, J. Catal., 2000, 194, 452-460.
S. Kuld, M. Thorhauge, H. Falsig, C. F. Elkjær, S. Helveg, I.
Chorkendorff and J. Sehested, Science, 2016, 352, 969-974.
T. Lunkenbein, J. Schumann, M. Behrens, R. Schlögl and M.
G. Willinger, Angew. Chem., Int. Ed., 2015, 54, 4544-4548.
J. Toyir, P. Ramı
Homs, Appl. Catal., B, 2001, 34, 255-266.
J. Toyir, P. Ramırez de la Piscina, J. L. G. Fierro and N. s.
́rez de la Piscina, J. L. G. Fierro and N. s.
́
Homs, Appl. Catal., B, 2001, 29, 207-215.
K. Larmier, W. C. Liao, S. Tada, E. Lam, R. Verel, A. Bansode,
A. Urakawa, A. Comas-Vives and C. Copéret, Angew.
Chem., Int. Ed., 2017, 56, 2318-2323.
K. Samson, M. Śliwa, R. P. Socha, K. Góra-Marek, D. Mucha,
D. Rutkowska-Zbik, J. F. Paul, M. Ruggiero-Mikołajczyk, R.
Grabowski and J. Słoczyński, ACS Catal., 2014, 4, 3730-
3741.
J. F. Edwards and G. L. Schrader, J. Phys. Chem., 1984, 88,
5620-5624.
T. Fujitani, I. Nakamura, T. Uchijima and J. Nakamura, Surf.
Sci., 1997, 383, 285-298.
18.
19.
20.
21.
O. Martin, C. Mondelli, A. Cervellino, D. Ferri, D. Curulla-
Ferré and J. Pérez-Ramírez, Angew. Chem., Int. Ed., 2016,
55, 11031-11036.
Conflicts of interest
There are no conflicts to declare.
22.
23.
24.
25.
26.
F. Arena, G. Italiano, K. Barbera, S. Bordiga, G. Bonura, L.
Spadaro and F. Frusteri, Appl. Catal., A, 2008, 350, 16-23.
E. Lam, K. Larmier, S. Tada, P. Wolf, O. V. Safonova and C.
Copéret, Chin. J. Catal., 2019, 40, 1741-1748.
S. Kuld, C. Conradsen, P. G. Moses, I. Chorkendorff and J.
Sehested, Angew. Chem., Int. Ed., 2014, 53, 5941-5945.
A. Le Valant, C. Comminges, C. Tisseraud, C. Canaff, L.
Pinard and Y. Pouilloux, J. Catal., 2015, 324, 41-49.
C. Tisseraud, C. Comminges, T. Belin, H. Ahouari, A.
Acknowledgements
E.L., G.N., K.L., D.L. and P.W. were supported by the SCCER Heat
and Energy Storage program (InnoSuisse). We acknowledge PSI
Super-XAS for beamtime (proposal #20180825). Scott R.
Docherty (ETH Zürich) and Jan Alfke (ETH Zürich) are
acknowledged for helpful discussions and assistance in the
processing of the XAS data.
6 | J. Name., 2012, 00, 1-3
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