Promotional Effect of Ag on the Catalytic Decomposition of N<sub>2</sub>O in the Presence of O<sub>2</sub> over the Al<sub>2</sub>O<sub>3</sub>-Supported Rh Catalyst
Yuan Jing, Chenxi He, Ningqiang Zhang, Y. Murano, Ryo Toyoshima, Hiroshi Kondoh, Yuuta Kageyama, Hironori Inomata, Takashi Toyao, Ken‐ichi Shimizu
Abstract
Catalytic decomposition of N 2 O into N 2 and O 2 is one of the most important techniques for removing N 2 O from the atmosphere to curb global warming. Supported RhO x catalysts are known to show high efficiency for N 2 O decomposition, even in the presence of O 2, compared with other materials, such as supported metal oxides and Fe-based zeolite catalysts. In this study, the addition of Ag was found to enhance the efficiency of an Al 2 O 3 -supported RhO x catalyst (RhO x /Al 2 O 3 ) for N 2 O decomposition. The promotional effect of Ag was investigated using various operando spectroscopic methods, including X-ray absorption spectroscopy, diffuse reflectance UV–vis spectroscopy (DR UV–vis), ambient-pressure X-ray photoelectron spectroscopy, and kinetic studies. The results demonstrated that the addition of Ag enhanced the catalytic efficiency of the supported RhO x catalysts by enhancing the thermal reduction of Rh oxide, which was identified as the rate-determining step, especially at low temperatures.