Enhanced CH(3)OH selectivity in CO(2) hydrogenation using Cu-based catalysts generated via SOMC from Ga(III) 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 SiO(2) and (ii) subsequent grafting of a Cu(I) precursor, [Cu(O(t)Bu)](4), followed by a treatment under H(2) to generate CuGa(x) alloys. This material is highly active and selective for CO(2) hydrogenation to CH(3)OH. In situ X-ray absorption spectroscopy shows that gallium is oxidized under reaction conditions while copper remains as Cu(0). 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.