TPR-XAFS study for water formation reaction of precious metal nanoparticle catalysts

貴金属微粒子触媒における水生成反応のTPR-XAFS法による研究

松村 大樹   ; 辻 卓也  ; 西畑 保雄; 谷口 昌司*; 田中 裕久*

Matsumura, Daiju; Tsuji, Takuya; Nishihata, Yasuo; Taniguchi, Masashi*; Tanaka, Hirohisa*

Hydrogen removal system with a catalyst is one of the candidates for hydrogen mitigation. In situ and time-resolved structure change of precious metal nanoparticle catalysts during water formation reaction was observed by using simultaneous measurement of temperature-programmed reaction and X-ray absorption fine structure (TPR-XAFS). We have observed sudden increase of carbon dioxide and water molecules, and sudden decrease of hydrogen is observed at around 110 C during TPR-XAFS study. This indicates that the adsorbed carbon monoxide was quickly decomposed and the surface of Pt metal nanoparticles was fast covered by oxide. In the case of CZY support sample, the continuous generation of water and carbon dioxide molecules were observed at room temperature. This means that the water formation reaction proceeds even at room temperature and under the existence of carbon monoxide.