Nature of Ni and Cu Species in Reduced Bimetallic $Ni-Cu/Al_20_3$ Catalysts

摘要

It is well known that $Ni^{2+}$ ions in calcined $Ni/gamma-A1_20_3$ catalysts are in a spinel-like phase, occupying both tetrahedral and octahedral sites,[1-3] and are not reduced on treatment with $H_2$ even at high temperatures (770 K). In calcined $Cu/gamma-Al_20_3$ catalysts, copper is similarly present in a spinel-like phase, [1,2,4] CuO segregating out at high copper loading[5] in this catalyst, however, the $Cu^{2+}$ ions are reducible on treatment with $H_2$.