Insight into the positive effect of Cu0/Cu+ ratio on the stability of Cu-ZnO-CeO2 catalyst for syngas hydrogenation

Abstract Cu-ZnO based catalysts are of industrial importance for methanol synthesis. In this work, Cu-ZnO-CeO2 (CZCe) catalyst has been prepared via conventional co-precipitation technique and applied for syngas hydrogenation to methanol with the purpose to study the effect of reversible redox metal oxide (ceria) on the distribution of valence state of active Cu species. Herein, CZCe catalyst exhibited the outstanding catalytic performance with initial methanol yield as high as 0.665 g·g–1 cat.·h–1 and the STYMeOH could well be maintained with a high value (0.600 g·g–1 cat.·h–1) at 230 °C after 70 h of evaluation, which exceeded the reference Cu-ZnO-Al2O3 (CZAl) catalyst prepared by the same method. The excellent performance could be attributed to ceria doping tended to dynamically tune the distributions and/or concentrations of Cu+ and Cu° species on the catalyst surfaces and retard the conversion of Cuδ+ (δ