Catalytic Co-Conversion of CH4 and CO2 Mediated by Rhodium-Titanium Oxide Anions RhTiO2.

Catalytic co-conversion of methane with carbon dioxide to produce syngas (2H2 + 2CO) involves complicated elementary steps and almost all the elementary reactions are performed at the same high temperature conditions in practical thermocatalysis. Here, we demonstrate by mass spectrometric experiments that RhTiO2- promotes the co-conversion of CH4 and CO2 to free 2H2 + CO and an adsorbed CO (COads) at room temperature; the only elementary step that requires the input of external energy is desorption of of COads from the RhTiO2CO- to reform RhTiO2-. This study not only identifies a promising active species for dry (CO2) reforming of methane to syngas, but also emphasizes the importance of temperature control over elementary steps in practical catalysis, which may significantly alleviate the carbon deposition originating from the pyrolysis of methane.