Interaction between NO and C2H4 on rh-loaded CeOx(111)

The interaction between NO and C2H4 was studied on ceria-supported Rh model catalysts (Rh/CeOX)). When the ceria is fully oxidized the primary reactio n products observed in TPD are NO, N-2. CO, and H2O. This is similar to wha t is observed on Rh(lll) except that CO results from the reduction of the C eO2 by the C in the C2H4 On highly reduced ceria the only hydrogen-containi ng products are H-2 and a small amount of NH3. The O that comes from NO dec omposition on Rh migrates to the CeOX before H2O formation occurs. N-2 and CO desorb from Rh/CeOX at a higher temperature than from Rh/CeO2. Soft X-ra y photoemission indicates that the NO and C2H4 do not strongly interact to form new intermediates on Rh/CeO2. As the molecules decompose they produce N and C atoms on the surface, which eventually react to form N-2 or CO. The C and N do combine on reduced Rh/CeOX. CN is formed between 400 and 500 K. The CN produces more complex CXNY species at higher temperatures. These co mplexes decompose near 700 K to produce N-2 and CO. There are no desorption products that contain both C and N.