Influence of support acidity and Ce3+ additives on the reactivity of nickel particles highly dispersed on various oxide supports

Important modifications to the reactivity of metallic nickel highly dispersed on various oxide supports have been observed. These vary according to the acidity of the support and the presence of Ce3+ additives. The loss or attenuation of hydrogen chemisorption properties and catalytic activity in butane hydrogenolysis seems to be correlated to the acidity of the support, which leads to a total or partial coverage of the metallic surface during the reduction process by hydrogen, which remains strongly chemisorbed up to high temperatures.The presence of Ce3+ additives causes an increase in the catalytic activity in the CO/H2 reaction and a significant shift of the selectivities in favour of the formation of heavier hydrocarbons from both the hydrogenation of CO and the hydrogenolysis of butane.These results are discussed in terms of strong metal–support interactions and concomitant modifications of the electronic environment of the metal.