CO₂ hydrogenation over CoAl based catalysts: Effects of cobalt-metal oxide interaction

The pivotal role of CO₂ hydrogenation in mitigating emissions and generating value-added fuels and chemicals underscores the significance of catalysts in achieving high efficiency in this process. The influence of metal-metal oxide interactions on catalyst performance has been widely acknowledged. In this study, Co-metal oxide interaction is tailored by calcining a mixed CoAl hydroxide (i.e., CoAl layered double hydroxide and Al hydroxide) at different temperatures and subsequently explored its impact on CO₂ hydrogenation. The findings reveal that a moderate Co-metal oxide interaction results in a balanced Co⁰-Co²⁺ synergy. This synergy, in turn, facilitates CO₂ conversion through a HCOO route at the Co⁰-Co²⁺ interface, leading to elevated turnover frequencies for CO₂ conversion and the production of methane with a selectivity surpassing 98%, while methanol and ethanol are generated as minor byproducts.