Promoting hydrogen spillover of NiFe/CeO2 catalyst with plasma-treatment for CO2 methanation

Hydrogen spillover is the key step during the CO2 methanation process that provides active hydrogen species for hydrogenation and facilitates the reaction at lower temperatures. This work features the synthesis of CeO2-supported NiFe alloy catalysts, and the subsequent activation using plasma treatment (PT). The PT catalysts exhibit a considerable improvement in performance at low temperatures as compared to the calcined (untreated) catalysts. The considerable enhancement in catalytic properties could be appropriate to the abundant hydroxyl (OH−) groups and the great hydrogen spillover ability of the PT catalysts. Furthermore, temperature-programmed surface reduction (TPSR) was used to determine the hydrogenation and CH4 generation temperatures and to reveal the promotion of PT catalysts. Formate was considered the key intermediate during the CO2 methanation process according to the in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) results.