Structural Disorder of AlMg‐Oxide Phase Supporting Cu/ZnO Catalyst Improves Efficiency and Selectivity for CO₂ Hydrogenation to Methanol

Abstract

The performance of the Cu/ZnO catalyst system with the AlMgoxide phase is studied for CO 2 hydrogenation to methanol. The catalyst is prepared by thermal treatment of the hydrotalcite phase containing intimately mixed metal cations in the hydroxide form. CuO in the presence of ZnO and disordered AlMg-oxide phase gets easily reduced to Cu during the hydrogenation reaction. Its catalytic activity at relatively low Cu metal content (~14 at.%) remains stable during 100 hours on stream at 260 °C with constant space-time yield for methanol (1 .8 g MeOH g cat À 1 h À 1 ) and high methanol selectivity (> 85 %) The improved performance is attributed to the neutralization of surface acidity, increased number of weak basic sites in the disordered phase, and lower tendency for coke formation.