Au/3DOM La_0.6Sr_0.4MnO₃: Highly active nanocatalysts for the oxidation of carbon monoxide and toluene

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• 作者：Yuxi Liu ; Hongxing Dai ; Jiguang Deng ; Xinwei Li ; Yuan Wang ; Hamidreza Ar ; iyan ; Shaohua Xie ; Huanggen Yang ; Guangsheng Guo
• 关键词：Supported gold catalyst ; Three-dimensionally ordered macroporous perovskite-type oxide ; Strontium-substituted lanthanum manganite ; Carbon monoxide oxidation ; Toluene oxidation
• 刊名：Journal of Catalysis
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：305
• 期：Complete
• 页码：146-153
• 全文大小：2830 K

文摘

Three-dimensionally ordered macroporous (3DOM) La_0.6Sr_0.4MnO₃ (LSMO) and its supported gold (xAu/LSMO, x = 3.4-7.9 wt % ) catalysts were prepared using the polymethyl methacrylate-templating and gas-bubble-assisted polyvinyl alcohol-protected reduction methods, respectively. There were good correlations of surface-adsorbed oxygen species concentration and low-temperature reducibility with the catalytic activity of the sample for CO and toluene oxidation. Among the LSMO and xAu/LSMO samples, 6.4Au/LSMO performed the best, giving T_{50 %} and T_{90 %} values of ?19 and 3 ¡ãC for CO oxidation and 150 and 170 ¡ãC for toluene oxidation, respectively. The apparent activation energies (31-32 and 44-48 kJ/mol) obtained over xAu/LSMO were much lower than those (45 and 59 kJ/mol) obtained over LSMO for the oxidation of CO and toluene, respectively. It is concluded that higher oxygen adspecies concentration, better low-temperature reducibility, and strong interaction between Au and LSMO are responsible for the excellent catalytic performance of 6.4Au/LSMO.