Methane interaction with silica and alumina supported metal catalysts

Six different transition metals - cobalt, nickel, ruthenium, rhodium, iridium and platinum have been supported on silica or alumina by means of the incipient wetness method. After drying and calcination at 773 K, they have been characterized by the hydrogen pulse chemisorption technique and by transmission electron microscopy. The interaction of CH4 with the catalyst surface has been studied by a temperature programmed surface reaction of methane and by examining the reactivity with hydrogen of the carbon deposits formed for three hours of reaction at 623 K in a flow of diluted methane. It has been found that the support exerts a great influence in the activity of dehydrogenation of methane and in the kind of carbonaceous species generated. It has also been proved that rhodium catalysts have a special ability to stabilize reactive carbon species (CP) hydrogenable between 423 K and 498 K.