Influence of Ga addition on the methanol synthesis activity of Cu/ZnO catalyst in the presence and absence of alumina

The influence of Ga addition to Cu/ZnO (CZ) methanol synthesis catalyst was investigated in the presence (CZA-Ga) and absence (CZ-Ga) of alumina. The reducibility of CZA-Ga was found to be more facile than CZ-Ga. The acidic strength of CZA-Ga was considerably decreased compared to CZA and CZ-Ga. In the presence of alumina, the addition of Ga to CZ improved the textural properties, resisted agglomeration of copper and showed higher activity and stability in methanol synthesis reaction from syngas. The easy reducibility and the appropriate acidity can be ascribed to the higher activity with high yield to methanol observed on CZA-Ga.