Highly stable and selective layered Co-Al-O catalysts for low-temperature CO2 methanation

A series of layered Co-Al-O catalysts derived from hydrotalcites for low-temperature CO2 methanation were prepared via a hydrothermal method and reduced at 500, 550, 600, 650, and 700 degrees C, respectively. The characterisation results from XPS and CO2 -TPD revealed that the Co-0 content and basic sites over these catalysts were firstly increased and then decreased with the reduction temperature increasing, which led to the efficient dissociation of H-2 and CO(2 )adsorption. In situ DRIFTS measurements revealed that the formation of CH4 proceeded via the hydrogenation of carbonate and formate as intermediates. A superior catalytic performance of CoAl-O-600 catalyst for CO2 methanation was achieved with a CO2 conversion of 74% and a CH4 selectivity of 99% at low temperature of 250 degrees C. Moreover, it exhibited excellent resistance to coking and sintering upon a 240 h time on stream operation.

Automated summary

A series of layered Co-Al-O catalysts were prepared via a hydrothermal method and reduced at different temperatures. The results showed that the Co-0 content and basic sites on the catalysts increased and then decreased with the reduction temperature, leading to effective hydrogen dissociation and CO2 adsorption. The CoAl-O-600 catalyst exhibited superior performance in CO2 methanation at low temperature and showed excellent resistance to coking and sintering.