Enhanced CH3OH selectivity in CO2 hydrogenation using Cu-based catalysts generated via SOMC from GaIII single-sites

Small and narrowly distributed nanoparticles of copper alloyed with gallium supported on silica containing residual Ga^III sites can be obtained via surface organometallic chemistry in a two-step process: (i) formation of isolated Ga^III surface sites on SiO₂ and (ii) subsequent grafting of a Cu^I precursor, [Cu(O^tBu)]₄, followed by a treatment under H₂ to generate CuGa_x alloys. This material is highly active and selective for CO₂ hydrogenation to CH₃OH. In situ X-ray absorption spectroscopy shows that gallium is oxidized under reaction conditions while copper remains as Cu⁰. This CuGa material only stabilizes methoxy surface species while no formate is detected according to ex situ infrared and solid-state nuclear magnetic resonance spectroscopy.

Contact

Dr Olga Safonova
SuperXAS beamline
Operando spectroscopy group & Laboratory for Synchrotron Radiation and Femtochemistry (LSF)
Swiss Light Source, Paul Scherrer Intitute
5232 Villigen-PSI, Switzerland
Telephone: +41 56 310 58 05
E-mail: olga.safonova@psi.ch

Original Publication

Enhanced CH₃OH selectivity in CO₂ hydrogenation using Cu-based catalysts generated via SOMC from Ga^III single-sites  

Erwin Lam, Gina Noh, Ka Wing Chan,  Kim Larmier,  Dmitry Lebedev,  Keith Searles, Patrick Wolf, Olga V. Safonova  and Christophe Cop´eret

Chemical Science, 25 February 2020
DOI: 10.1039/d0sc00465k