CO2 Methanation over Ni catalysts supported on Carbon-Ceria composites – A ME-PSD-DRIFTS study

In the quest to develop a novel supporting material for CO2 methanation catalysts, a composite of activated carbon and CeO2 was developed since CeO2 is known to improve the low-temperature catalytic performance of the catalysts in CO2 methanation, although it is composed of a rare-earth metal. The resultant Ni on carbon-ceria composite catalyst afforded an excellent conversion of around 87% with almost complete selectivity to methane and excellent stability at a favorably low reaction temperature of 370 °C, similar to the performance obtained with Ni on pure CeO2. Therefore, the composite of carbon with CeO2 in the supporting material allowed for an efficient reduction in the usage of the expensive rare-earth CeO2 since it was able to achieve a similar performance. The reaction mechanism on both catalysts was investigated using the emerging ME-PSD-DRIFTS technique, and it was found that a partial modification in the supporting material of the catalysts can lead to different mechanisms of CO2 methanation.