In situ infrared study of catalytic decomposition of NO on carbon-supported Rh and Pd catalysts

The direct catalytic decomposition of NO on Rh/Al2O3, Rh/C, Pd/Al2O3, and P d/C catalysts was investigated at 673 K by in situ infrared (IR) coupled wi th mass spectroscopy (MS). NO decomposition on these catalysts initially pr oduced N-2 and adsorbed oxygen. Different catalysts exhibit different capab ilities for manipulating adsorbed oxygen. Rh/Al2O3 shows little activity fo r oxygen desorption, resulting in loss of catalyst activity; Rh/C shows the ability for promoting the adsorbed oxygen-carbon reaction, removing oxygen in the form of CO2; Pd/Al2O3 shows some activity for O-2 desorption. Use o f carbon as a support for Pd promotes O-2 desorption, resulting in improvem ent of NO decomposition activity. The in situ IR results provide evidence t o support the behavior of adsorbed oxygen on carbon-supported Rh and Pd cat alysts. (C)2000 Elsevier Science B.V. All rights reserved.