CO Preferential oxidation promoted by UV irradiation in the presence of H2 over Au/TiO2

被引：19

作者：

Dai, Wenxin ^{[1
]}

Chen, Xun ^{[1
]}

Wang, Xuxu ^{[1
]}

Liu, Ping ^{[1
]}

Li, Danzhen ^{[1
]}

Li, Guanshe ^{[1
]}

Fu, Xianzhi ^{[1
]}

机构：

[1] Fuzhou Univ, Res Inst Photocatalysis, State Key Lab Breeding Base Photocatalysis, Fuzhou 350002, Peoples R China

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2008年 / 10卷 / 22期

关键词：

D O I：

10.1039/b718541c

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The catalytic oxidation of CO was performed over Au/TiO2 under UV irradiation in the presence of H-2 in different reaction systems. It was found that the introduction of H-2 enhanced the CO thermocatalytic oxidation in a CO pre-introduced system (CO/O-2 vs. CO/H-2/O-2), but suppressed that in an O-2 pre-introduced (O-2/CO vs. O-2/H-2/CO) system. Although the CO oxidation in both CO/H-2/O-2 and O-2/ H-2/CO systems could be remarkably enhanced under UV irradiation, the oxidation of H-2 was suppressed under UV irradiation. It was proposed that the dissociative chemisorption H (equivalent to Ti-H) at surface oxygen vacancy sites of TiO2 could act as both the electron-acceptors for the photogeneration electrons and the electron-donors for the chemisorbed O-2 at TiO2, and thus enhance the CO oxidation during the coinstantaneous process of thermocatalysis and photocatalysis. The suppression of H-2 thermocatalytic oxidation under UV irradiation might be ascribed to the electron transfer effect, i.e., the dissociative chemisorption H on Au (Au-H) could be desorbed at the H-2 molecule via accepting the photogenerated electrons from TiO2.

引用

页码：3256 / 3262

页数：7

共 33 条

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