Hydrogen Spillover in Catalytic Reactions: I. Activation of Alumina

Abstract

Abstract Hydrogen, adsorbed and dissociated by the metal (Pt or Ni) supported on alumina, migrates on admixed alumina and, depending on the nature of the metal, of alumina and on the temperature (i) participates in some reactions such as hydrogenation of ethylene, or (ii) activates alumina for hydrogenation (ethylene, butenes, benzene) or isomerization (methylcyclopropane) reactions, occurring at fairly low temperatures with high selectivity for some products. This new behavior of alumina is easily observed because the catalyst (metal on alumina) is removed from admixed alumina in a special design reactor, provided with a lifting device. These selective reactions on alumina are masked by the metal part of the oxide-supported catalyst in the conventional reactors where the catalyst cannot be separated from admixed oxide.