Ru/CeO2 catalyst derived from Ce-based MOF for highly efficient catalytic CO2 methanation integrated with renewable hydrogen
Yucan He, Dongsen Mao, Qiangsheng Guo, Jun Yu
Abstract
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 CeO 2 by pyrolysis of Ce-MOF, and investigated for the CH 4 synthesis via CO 2 hydrogenation. Among the catalysts, Ru catalyst supported on the CeO 2 -B derived from Ce-BDC exhibited a highly competitive efficiency for CO 2 methanation, giving a CH 4 selectivity of 100% with a CO 2 conversion of 62% at 275 °C and 0.1 MPa, and the CH 4 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 CeO 2 -B derived from Ce-BDC caused to the stronger interaction between Ru and CeO 2 -B, which promoted the CO 2 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 CH 4 is a more competitive way of CO 2 hydrogenation to CH 4 . • CeO 2 supported Ru catalysts were constructed based on the heat-treatment strategy of Ce-MOFs. • Ru catalyst supported on CeO 2 -B exhibited a highly competitive efficacy for CO 2 methanation. • More oxygen vacancies and surface oxygen species were formed on CeO 2 -B surface. • The stronger interaction between Ru and CeO 2 -B promoted the CO 2 adsorption and hydrogenation. • The route of HCOO* into CH 4 is a more competitive way of CO 2 hydrogenation to CH 4 .