CO2 Hydrogenation to CH3OH over Cu‐Based Catalysts: Primary and Side Reactions

Abstract

AbstractCarbon dioxide (CO2) hydrogenation to methanol (CH3OH) is one of the most promising approaches to provide this platform chemical and to close carbon cycles. In this minireview, we systematically analyze primary and secondary reactions which can take place in this reaction over Cu‐based catalysts. In addition to repeatedly discussed reverse water gas shift reaction (RWGS) and CH3OH production directly from CO2, we consider decomposition, dehydration, dehydrogenation, and steam reforming of the desired alcohol. These reactions are usually ignored in the studies dealing with CO2 hydrogenation to CH3OH but can worsen the catalyst efficiency. Apart from the corresponding thermodynamic analysis, proposed reaction mechanisms and active sites are described and discussed. The effects of co‐fed water, CH3OH and methyl formate on catalyst performance are critically scrutinized, too. We also provide several criteria for unambiguous comparison of different catalysts in terms of CH3OH selectivity and their activity.