Effect of Cs and Ba promoters on Ni/graphite catalysts for CO2 conversion via the reverse water gas shift reaction

Abstract

Obtaining syngas from CO2 and green hydrogen via the reverse water gas shift (RWGS) reaction is a promising strategy for mitigating the greenhouse effect. Additionally, CO obtained as the product holds significant potential in the syngas-based chemical industry. In this context, we developed efficient Ni-based catalysts for the RWGS reaction at a low temperature. In our approach, we selected Cs and Ba as catalytic promoters and utilized high-surface-area graphite (HSAG400) as a support to maximize the interaction between the metal and promoter. Our study revealed that both promoters helped in enhancing the CO2 conversion but had opposite effects in the RWGS reaction. In particular, the use of the Cs promoter boosted the CO selectivity up to 95%, while the addition of Ba proved to be detrimental to CO selectivity.