Characterization of palladium-copper bimetallic catalysts supported on silica and niobia

Silica and niobia Pd-Cu supported bimetallic catalysts were characterized by temperature-programmed reduction (TPR), hydrogen chemisorption and infrared spectroscopy of adsorbed carbon monoxide. On catalysts reduced at 573 K, the metal-metal interaction was confirmed from the analysis of TPR profiles and the decreased capacity of hydrogen chemisorption with increasing copper content. After reduction at 773 K, the palladium/niobia catalyst displays a SMSI effect; however, the increase in copper content in the bimetallic catalyst led to a suppression of the SMSI.