RELATIONSHIP BETWEEN OXIDATION-STATES OF COPPER SUPPORTED ON ALUMINA AND ACTIVITIES FOR CATALYTIC COMBUSTION OF NH3

The relationship between the oxidation state of Cu supported on an alu mina catalyst (Cu/Al2O3) and the activity for combustion of NH3 was in vestigated. Combustion of NH3 on the catalyst treated in hydrogen at 8 00 degrees C occurred at lower temperature than on the catalyst treate d in air. It was also much better than Pt and Ph catalysts for the con version of NH3 to N-2. Characteristics of the catalyst were investigat ed by XRD, XPS, and the N2O pulse injection method to understand the r eason of its high catalytic activity. The reason of the high activity of the catalyst treated in hydrogen at the high temperature was attrib uted to the lower oxidation state of Cu in the catalyst.