Influence of trivalent metal ions on the surface structure of a copper-based catalyst for methanol synthesis

The method of doping trivalent metal ions into a copper-based catalyst for methanol synthesis is effective in modifying the surface structure of the catalyst. The promotion effect and its relation to catalytic activity for hydrogenation of CO to methanol after doping with trivalent metal ions such as Al3+, SC3+, and Cr3+ into Cu-ZnO have been investigated by XRD, ESR, XPS, TPR, and the evaluation of catalytic activity. The results show that doping trivalent metal ions into ZnO assists in the formation of monovalent cationic defects on the surface of ZnO. These monovalent cationic defects both enrich and stabilize monovalent copper on the surface of copper-based catalysts for methanol synthesis during reduction and reaction. They increase catalytic activity for methanol synthesis and extend the life of catalysts. (C) 1999 Elsevier Science B.V. All rights reserved.