Probing synergistic effect of active Cu0 species and surface acidity of chainlike ZSM-5 supported copper catalysts in methanol dehydrogenation to methyl formate

A series of chainlike ZSM-5 supported Cu catalysts with the addition of citric acid (CA) was conveniently prepared using a complexation-impregnation method and employed in the methanol dehydrogenation to methyl formate (MF). The catalytic performance of Cux/CZ5 first increased and then decreased with increasing CA/Cu ratio, reached 35.0% methanol conversion and 88.3% MF selectivity for Cu1.8/CZ5, significantly higher than that of Cu/CZ5. The superior catalytic performance might be principally explained by the higher Cu0 concentration combined with abundant Bronsted acid sites, which are responsible for methanol conversion and MF selectivity, respectively. This work provides new insights into the synergy between Cu0 species and surface acidity of Cux/CZ5 catalysts for methanol dehydrogenation and offers a feasible and effective strategy for enhancement of the catalytic performance of copper-based catalysts.