Ru/CeO2 catalyst derived from Ce-based MOF for highly efficient catalytic CO2 methanation integrated with renewable hydrogen

A series of highly ordered microporous Ce-based metal-organic frameworks (MOFs) were synthesized as the precursors for catalyst construction. The corresponding Ru catalysts were prepared by Ru impregnation on the derived CeO₂ by pyrolysis of Ce-MOF, and investigated for the CH₄ synthesis via CO₂ hydrogenation. Among the catalysts, Ru catalyst supported on the CeO₂-B derived from Ce-BDC exhibited a highly competitive efficiency for CO₂ methanation, giving a CH₄ selectivity of 100% with a CO₂ conversion of 62% at 275 °C and 0.1 MPa, and the CH₄ productivity reached 0.49 mol/(mol_Ru·h). Characterization results revealed that more oxygen vacancies and corresponding surface oxygen species formed on the surface of CeO₂-B derived from Ce-BDC caused to the stronger interaction between Ru and CeO₂-B, which promoted the CO₂ adsorption and hydrogenation capacity of the catalyst, resulting in its better catalytic property. In situ diffuse reflectance infrared Fourier transform (DRIFT) studies further revealed that the route of HCOO* into CH₄ is a more competitive way of CO₂ hydrogenation to CH₄.