Synergistic Catalysis of Al and Zn Sites of Spinel ZnAl2O4 Catalyst for CO Hydrogenation to Methanol and Dimethyl Ether

Activation and surface reactions of CO and H 2 on spinel ZnAl 2 O 4 catalyst under CO hydrogenation reaction conditions were studied using temperature-programmed surface reaction spectra and in situ diffuse reflectance Fourier transform infrared spectroscopy. CO and H 2 activation was found to occur at the Al and Zn sites of ZnAl 2 O 4 catalyst to form active bidentate formate species and reversibly adsorbed hydrogen species for methanol/diemthyl etherproduction, respectively. The hydrogenation of resulting bidentate formate species at the Al site is the rate-controlling step and exhibits a barrier of 83.8 kJ/mol. These results reveal the synergistic catalysis of Al and Zn sites of spinel ZnAl 2 O 4 and rate-controlling step in catalyzing CO hydrogenation to methanol/dimethyl ether, which greatly deepens fundamental understanding of oxides-catalyzed CO hydrogenation reaction.