Surface Catalytic Reactions Assisted by Gas Phase Molecules on Supported Co-ensemble Catalysts

摘要

This paper presents a new aspect of surface catalytic reactions assisted by gas phase molecules in the catalytic NO reduction with CO on supported Co~(2+)-ensemble catalysts prepared by chemical vapor deposition of Co_2(CO)_8 on Al_2O_3 and TiO_2. NO molecules adsorbed on Co~(2+) sites to form Co dinitroslys which were surface reaction intermediates as characterized by FT-IR, whereas no CO molecules adsorbed on the surfaces. CO molecules undetectable at the catalyst surfaces promoted the NO adsorption, the reactivity of Co dinitrosyls and a change in the dinitrosyl structure. A possible mechanism for the observed phenomenon is proposed.