Inverse supported Al2O3/Coº catalysts for enhanced CO2 hydrogenation

Abstract

Inverse catalysts, characterized by their distinctive interfaces, demonstrate exceptional catalytic activity for CO₂ conversion. This study explores the synthesis of an Al-Co oxide/Co⁰ inverse catalyst through the reduction of a Co-Al oxide with a high Co content, achieved by modulating the Co/Al ratio in the oxide precursor. The resulting inverse catalyst significantly enhances CO₂ hydrogenation, yielding increased production of methane, methanol, and ethanol, with a notable amplification in ethanol output. Amongst, the catalyst with a Co/Al ratio of 9:1 achieves high yields for methane (32,131 μmol/g, methanol (461 μmol/g), and ethanol (123 μmol/g). To elucidate the structure and reaction mechanism, the inverse catalyst was also characterized using a suite of techniques. It is posited that the abundance of active sites on the inverse catalyst, coupled with its moderate H binding affinity, facilitates CO₂ activation and conversion. This is particularly evident in the enhanced coupling of *HCOO and *CH₃ intermediates, which promotes ethanol synthesis. This research not only sheds light on the interactions between metal and metal oxide within Co-based catalysts for CO₂ hydrogenation but also proposes a facile method for crafting efficient catalysts for such processes.