THE EFFECTS OF M2O3 ON STABILIZING MONOCOPPER OVER THE SURFACE OF CU-ZNO-M2O3 CATALYSTS FOR METHANOL SYNTHESIS

The effects of M2O3 (M = Al, Sc etc.) in Cu-ZnO-M2O3 catalysts on meth anol synthesis at low pressure were studied with ESR, XPS and TPR spec troscopy. The results of ESR showed that the generation of monovalent cationic defects was because the valence state and electronic charge o n the ZnO lattice lost their balance as M3+ doped into ZnO. The induce d effect by SC3+ is stronger than that by Al3+. The results of XPS and TPR indicated that the amount and stabilization of Cu+ on the surface of reduced copper-based catalyst and its catalytic activity were affe cted by the monovalent cationic defects on the surface of ZnO.