ESR detection of copper ion clusters in the Cu-Zn-Al oxide catalysts for methanol synthesis

It was found by ESR spectroscopy that the treatment of the Cu-Zn-Al oxide catalysts for methanol synthesis with pyridine did not produce isolated pyridinate complexes. In this case, three types of copper clusters were formed; two of them were assigned to the ordered Jahn-Teller clusters. It was suggested that the cluster structures consist of the Cu 2+ -O-M-O-Cu 2+ oxide fragments (where M is the Al 3+ , Zn 2+ , and Cu 2+ ion), which were not decomposed upon treatment with pyridine.