Boosting low temperature CO₂ methanation by tailoring Co species of CoAlO catalysts

The development of low-temperature CO₂ methanation catalysts with excellent performance has been challenging. Herein, we report a CoAlO catalyst derived from layered double hydroxide (LDH) that modulates the Co species of a multifunctional catalyst through a reduction process. The CoAlO catalyst with a surface-coated CoO film achieved CO₂ conversion up to 29.0 % at 160 °C, which was superior to that of noble metal catalysts. The multiple characterizations were used to reveal the relationship between the catalytic activity and the chemical state of Co species. The results showed that the reaction followed the H-assisted activation pathway, where the rate of formate intermediates generation determined the overall reactivity. Meanwhile, the reduction–oxidation (RO) process in the catalyst preparation and the water generated in the reaction could reduce the size of Co particles, which were favorable for CO₂ activation. This work offers a promising catalyst design for low-temperature methanation reaction.