Decomposition of formic acid on the (110)-microfaceted surface of TiO{sub 2}(100): Competing processes and the role of Ti{sup 3+} sites
- Pacific Northwest Lab., Richland, WA (United States)
The decomposition of formic acid was examined on the (110)-microfaceted surface of TiO{sub 2}(100). This surface possesses rows of 3-coordinate Ti{sup 3+} sites at each facet ridge. Formic acid decomposes on this surface by two channels. The first channel is marked by first-order CO desorption at 550 K. This channel is assigned to surface formate decomposition, as observed on other TiO{sub 2} surface. However, unlike these studies, which note a competition between CO + H{sub 2}O and CO{sub 2} + H{sub 2}, only CO is observed from the (110)-microfaceted TiO{sub 2}(100) surface. Also, formate decomposition on TiO{sub 2}(100) does not result in H{sub 2}O desorption, although water desorption does occur below 400 K from formic acid conversion to formate. The fate of the formate proton is not yet known. The second channel is marked by the desorption of formaldehyde between 500 and 550 K. Ti{sup 3+} sites act as reduction centers for the transformation of formate to formaldehyde. The process appears to be catalytic. The kinetics for CO and H{sub 2}CO desorption are different.
- OSTI ID:
- 126111
- Report Number(s):
- CONF-950402--
- Country of Publication:
- United States
- Language:
- English
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