1. Deactivation of Pt-Au/TiO2-CeO2 catalyst for co-oxidation of HCHO, H2 and CO at room temperature: Degradations of active sites and mutual influence between reactants.
- Author
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Hong, Xiaowei, Chen, Jianjun, Peng, Yue, Song, Hua, Wang, Chizhong, and Li, Junhua
- Subjects
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CATALYST poisoning , *CATALYTIC activity , *BIOCHEMICAL substrates , *CARBON monoxide , *SELF-poisoning , *TEMPERATURE - Abstract
Pt-Au/TiO 2 -CeO 2 catalyst for the co-oxidation of HCHO, H 2 and CO at 25 °C. • The Pt-Au/TiO 2 -CeO 2 catalyst exhibited high catalytic activity for the co-oxidation of HCHO, H 2 and CO at room temperature. • CO restrained the oxidation of HCHO and H2 due to the CO self-poisoning effect. • H2 promoted the oxidation of HCHO and CO because of the generation of OOH and OH active species. • The deactivation was due to chemical state changes of active site and the accumulation of carbonates-like species. The deactivation origins of the Pt-Au/TiO 2 -CeO 2 catalyst for co-oxidation of formaldehyde (HCHO), hydrogen (H 2) and carbon monoxide (CO) at room temperature were studied by means of XRD, BET, H 2 -TPR, O 2 -TPD, XPS and in-situ DRIFTS. The results suggested that the catalyst deactivation was mainly caused by the reduction of Au+ species, the decrease of Ce3+ species and interaction weakness between active components and support. Moreover, during the co-oxidation process, CO showed a negative influence on the oxidation of HCHO and H 2 due to the CO self-poisoning effect, whereas H 2 promoted the oxidation of HCHO and CO because of the generation of OOH and OH active intermediates from the H 2 oxidation. Meanwhile, the accumulations of carbonate-like species as well as the production of H 2 O on the deactivated catalyst were also observed, accounting for the complete catalyst deactivation. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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