Active sites for CO2hydrogenation to methanol on Cu/ZnO catalysts.
The active sites over commercial copper/zinc oxide/aluminum oxide (Cu/ZnO/Al2O3) catalysts for carbon dioxide (CO2) hydrogenation to methanol, the Zn-Cu bimetallic sites or ZnO-Cu interfacial sites, have recently been the subject of intense debate. We report a direct comparison between the activity of ZnCu and ZnO/Cu model catalysts for methanol synthesis. By combining x-ray photoemission spectroscopy, density functional theory, and kinetic Monte Carlo simulations, we can identify and characterize the reactivity of each catalyst. Both experimental and theoretical results agree that ZnCu undergoes surface oxidation under the reaction conditions so that surface Zn transforms into ZnO and allows ZnCu to reach the activity of ZnO/Cu with the same Zn coverage. Our results highlight a synergy of Cu and ZnO at the interface that facilitates methanol synthesis via formate intermediates.
Chemistry Division, Brookhaven National Laboratory, Upton, NY 11973, USA.
Shyam
0000-0002-5843-5889
S
Kattel
Facultad de Ciencias, Universidad Central de Venezuela, Caracas 1020-A, Venezuela.
Pedro J
0000-0002-6236-5545
PJ
Ramírez
Chemistry Division, Brookhaven National Laboratory, Upton, NY 11973, USA. jgchen@columbia.edu rodrigez@bnl.gov pingliu3@bnl.gov.|Department of Chemical Engineering, Columbia University, New York, NY 10027, USA.
Jingguang G
0000-0002-9592-2635
JG
Chen
Chemistry Division, Brookhaven National Laboratory, Upton, NY 11973, USA. jgchen@columbia.edu rodrigez@bnl.gov pingliu3@bnl.gov.|Department of Chemistry, State University of New York-Stony Brook, Stony Brook, NY 11790, USA.
José A
0000-0002-5680-4214
JA
Rodriguez
Chemistry Division, Brookhaven National Laboratory, Upton, NY 11973, USA. jgchen@columbia.edu rodrigez@bnl.gov pingliu3@bnl.gov.|Department of Chemistry, State University of New York-Stony Brook, Stony Brook, NY 11790, USA.
Ping
0000-0001-8363-070X
P
Liu