Characterization and reactivity analysis of hydrogen adspecies on platinum nano-particles supported on alumina

Abstract

The dispersion state of Pt nano-particles supported on Al 2O 3 was investigated by gas chemisorption. The amount of HH 2 chemisorption was larger than that of CO over the entire range of Pt dispersion. Pt dispersion beyond 100 % was estimated for Pt/Al 2O 3 with nano-sized Pt particles by HH 2 chemisorption. FT-IR measurements of hydrogen species adsorbed on Pt/Al 2O 3 with different Pt dispersions revealed that hydrogen species dissociatively adsorbed on Pt nano-particles and spilled over onto Al 2O 3. Hydrogen species dissociatively adsorbed on Pt nano-particles were highly reactive with NO at room temperature, leading to the formation of N 2. In contrast, hydrogen species spilled over onto the fringes of Pt particles reacted with NO to form N 2O.