催化作用
化学
选择性催化还原
红外光谱学
无机化学
磷酸盐
反应机理
密度泛函理论
水溶液
光谱学
吸收光谱法
光化学
核化学
物理化学
有机化学
计算化学
物理
量子力学
作者
Ningqiang Zhang,Jiahuan Tong,Shinta Miyazaki,Shirun Zhao,Hirokazu Kubota,Jing Yuan,Shinya Mine,Takashi Toyao,Ken‐ichi Shimizu
标识
DOI:10.1021/acs.est.3c05787
摘要
This study reports a comprehensive investigation into the active sites and reaction mechanism for the selective catalytic reduction of NO by NH3 (NH3-SCR) over phosphate-loaded ceria (P/CeO2). Catalyst characterization and density functional theory calculations reveal that H3PO4 and H2P2O6 species are the dominant phosphate species on the P/CeO2 catalysts under the experimental conditions. The reduction/oxidation half-cycles (RHC/OHC) were investigated using in situ X-ray absorption near-edge structure for Ce L3-edge, ultraviolet-visible, and infrared (IR) spectroscopies together with online analysis of outlet products (operando spectroscopy). The Ce4+(OH-) species, possibly adjacent to the phosphate species, are reduced by NO + NH3 to produce N2, H2O, and Ce3+ species (RHC). The Ce3+ species is reoxidized by aqueous O2 (OHC). The results from IR spectroscopy suggest that the RHC initiates with the reaction between NO and Ce4+(OH-) to yield Ce3+ and gaseous HONO, which then react with NH3 to produce N2 and H2O via NH4NO2 intermediates.
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