REACTION AND XRD STUDIES ON CU BASED METHANOL DECOMPOSITION CATALYSTS - ROLE OF CONSTITUENTS AND DEVELOPMENT OF HIGH-ACTIVITY MULTICOMPONENT CATALYSTS

摘要

A series of Cu based catalysts with and without ZnO have been studied for methanol decomposition in the absence of water. CO and H-2 are the major products. A significant amount of methyl formate is produced at low conversions and low reaction temperatures. Cu/ZnO based catalysts show high initial activity but quickly deactivate. This may be attributed to the dissolution of Zn into the Cu lattice. Without the component ZnO, other Cu based catalysts show good activity and better stability. Cr increases the stability of the Cu based catalysts but slightly reduces the selectivity to CO. The composition of Cr correlates with the yield of dimethyl ether. Among many other components on evaluated, a small amount of Ba, Mn and Si oxides strongly promote the Cu based catalysts in methanol decomposition. Cu, Cr, Si, O and Ba or Mn constitute the components of the highly active multicomponent catalyst. Characterizations of the catalysts combined with the compositional study suggest that metallic Cu is the active species for methanol decomposition. Silica enhances the activity probably by increasing the dispersion of Cu. [References: 37]