Effect of Structural Evolution of Gold Species Supported on Ceria in Catalyzing CO Oxidation
Effect of Structural Evolution of Gold Species Supported on Ceria in Catalyzing CO Oxidation
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DOI：
10.1021/acs.jpcc.9b00096
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发表时间：
2019-03
期刊：
影响因子：
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通讯作者：
Xiuxiu Wang;Xin-Pu Fu;Wei-wei Wang;Chao Ma;R. Si;Chunjiang Jia
中科院分区：
文献类型：
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作者：
Xiuxiu Wang;Xin-Pu Fu;Wei-wei Wang;Chao Ma;R. Si;Chunjiang Jia
原子分散的金催化剂用于低温（L-T）CO氧化的固有反应性仍然是一个难以捉摸的问题。在这里，两种原子分散的金具有不同的负载通过沉积沉淀法制备的纳米氧化铈负载作为L-T CO氧化催化剂进行了评价。两种金催化剂在催化CO氧化反应中表现出明显的差异。在1% Au/CeO 2（1wt%金负载）催化剂中的这些弱锚定的金物种显示在反应条件下增加的反应性，而在0.5% Au/CeO 2（0.5wt%金负载）催化剂中的这些强锚定的金物种是无活性的。原位漫反射红外光谱（DRIFTS）证实了1%Au/CeO 2催化剂中金物种从Aun+（1 ≤ n < 3）转变为Auδ+（0 < δ < 1），同时像差校正的扫描透射电镜（SEM）证实了部分原子分散的金物种转变为Auδ+（0 < δ <1）。
The intrinsic reactivity of atomically dispersed gold catalysts for low-temperature (L-T) CO oxidation remains an elusive issue. Here, two kinds of atomically dispersed gold with different loadings supported on nanoceria prepared via a deposition precipitation method were evaluated as catalysts for L-T CO oxidation. Much distinct differences in catalyzing CO oxidation behaviors were exhibited on the two kinds of gold catalysts. These weakly anchored gold species in the 1% Au/CeO2 (1 wt % gold loading) catalyst revealed increasing reactivity under the reaction condition, while these strongly anchored ones in the 0.5% Au/CeO2 (0.5 wt % gold loading) catalyst were inactive. For the 1% Au/CeO2 catalyst, in situ diffuse reflectance infrared spectroscopy (DRIFTS) proved gold species transformation from Aun+ (1 ≤ n < 3) to Auδ+ (0 < δ < 1), and simultaneously, aberration-corrected scanning transmission electron microscope measurements confirmed that partial atomically dispersed gold species transformed into gold...