Photocatalytic partial oxidation of methane to carbon monoxide and hydrogen over CIGS solar cell

Abstract

Methane valorization is one of the main challenges in the modern chemical industry. However, existing processes require high reaction temperatures. The alternative photocatalytic routes for methane valorization at ambient conditions would be highly attractive. Today, photovoltaic (PV) generation of electricity is one of the main sources of renewable energy. PV absorbers could be excellent candidates for photochemical applications. Herein, we report selective methane photocatalytic oxidation at ambient conditions into CO and H2 by conventional Cu(In,Ga)Se2 (CIGS) absorbers used in solar cells. A thin film of CIGS coated over Mo exhibits exceptional performance in methane partial oxidation to CO and H2 with a stable CO productivity of 2.4 mmol per gram of CIGS and a selectivity to CO of over 80%. The reaction proceeds via the facile dissociation of methane into disordered carbon and hydrogen over CIGS surface with subsequent regeneration of the surface by partial oxidation of carbon into CO.