Development of skeletal copper–chromia catalysts: I. Structure and activity promotion of chromia on skeletal copper catalysts for methanol synthesis Original Research Article

Studies of promotional effects of chromia on structure and properties of skeletal copper catalysts for methanol synthesis have been carried out. Catalysts were prepared by selective dissolution of aluminum from CuAl2 alloy and, at the same time, precipitation of chromia on the surface of residual skeletal copper using a caustic solution containing sodium chromate. Deposition of chromia on the skeletal copper catalysts was found to greatly influence the pore structure and specific surface area, resulting in a relative decrease of pore diameter and remarkable enhancement of specific surface area, while the total pore volume was maintained constant. Significant improvements to methanol synthesis activity and selectivity were achieved by adding small amounts of chromia (about 3.5 wt.%) to the skeletal copper. However, higher chromia loadings were found to be unfavorable for methanol synthesis reactions. The results obtained in this study suggest that chromia acts as a structural promoter and provides high specific copper surface area for methanol synthesis. The chromia-promoted catalysts produced by this method are likely to have applications in organic hydrogenation reactions and for the water gas shift reaction.