HIGH TEMPERATURE STABLE CATALYSTS

An improved method for preparing a catalytic composition that includes a calcined alumina aggregate in admixture with oxides that impart stability at high temperatures, which method comprises: forming an intimate mixture comprising an alumina-producing aluminum compound and, at least, two additional metal compounds, which on calcination provide the corresponding metal oxides, said metal compounds being composed of metals selected from the group consisting of a) chromium or tungsten or mixtures thereof and, at least, a metal of group ivb; b) a metal of the rare earths and, at least, a metal of group ivb; c) a metal of the rare earths and as or tungsten or mixtures thereof; d) a metal of the rare earths, chromium or tungsten or mixtures thereof and, in addition, at least one metal of group ivb, and e) a metal of the rare earths, chromium or tungsten or mixtures thereof and, in addition,, calcium, strontium, barium, silicon, tin or mixtures thereof; calcining said intimate mixture at a temperature of at least 850º c, except for the oxidic component e) which is subjected to 500º c, to form an oxidic and catalytically active aggregate thereof, characterized by a surface area of, at least, 20 m2/g, after calcination for 2 hours at 1,200º c; and incorporating a catalytically effective amount of a metal from the platinum group into said calcined mixture. (Machine-translation by Google Translate, not legally binding)