Doping effect of potassium permanganate on the performance of a copper/zinc oxide/alumina catalyst for methanol formation

The doping effect of potassium permanganate on the performance of a copper/zinc oxide/alumina catalyst for methanol synthesis was studied. It was found that doping with potassium permanganate appreciably enhanced the activity of the catalyst. The optimum nominal dosage of potassium permanganate was found to be 6.0 mol.%, The precursors and the calcined, reduced and syngas-treated catalysts undoped and doped with potassium permanganate were characterized by X-ray photoelectron spectroscopy and X-ray-induced Anger transition, powder X-ray diffraction, atomic absorption spectroscopy and temperature programmed oxidation. Based on the results of the characterization, it is suggested that the promotion effect is mainly caused by manganese and the nature of the effect is probably the increased affinity of the catalyst surface for oxygen which gives rise to increased surface oxygen and Cu1+ species under reaction conditions.