On the issue of the active site and the role of ZnO in Cu/ZnO methanol synthesis catalysts

The problem concerning the active site and the role of ZnO in Cu/ZnO-based methanol synthesis catalyst can be consistently explained based on the literature results by distinguishing CO₂ and CO hydrogenation. A discussion on CO and CO₂ hydrogenation covers the role of ZnO and the active site for methanol synthesis by hydrogenation of CO₂ over Cu/ZnO-based catalysts; Cu-Zn active site of the CO₂ hydrogenation; effect of the reduction-oxidation treatment upon the methanol synthesis by CO₂ hydrogenation; issues of the active site and the role of ZnO; role of surface oxygen on Cu catalysts; and spill over effect.