Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5426363 | Surface Science | 2006 | 7 Pages |
Formaldehyde adsorption and reaction have been studied on cerium oxide thin films that were vapor deposited on Ru(0Â 0Â 0Â 1). The formaldehyde behavior was examined as a function of temperature, exposure and Ce oxidation state. Formaldehyde chemisorbs on fully oxidized CeO2 as dioxymethylene, CH2O2. The dioxymethylene decomposes and desorbs as formaldehyde between 200Â K and 400Â K. No other products are formed. On reduced ceria, formaldehyde also adsorbs as dioxymethylene. In addition to the formaldehyde desorption between 200Â K and 400Â K, a more strongly bound form of dioxymethylene is formed that produces formaldehyde at 440Â K. Above 400Â K, some of the dioxymethylene reacts to form formate and methoxy on the surface. These species decompose to produce H2, CO and CH2O above 500Â K.