Hydrothermally synthesized MO-V-M-X oxide catalysts for the selective oxidation of hydrocarbons

A process for producing a catalyst comprising a mixed metal oxide having the empirical formula

• MOaVbMcXdOe
• wherein M is an element selected from the group consisting of Te, Sb and Nb,
• wherein X is an element selected from the group consisting of Sc, Y, La, Re, Ir, Cu, Ag, Au, Zn, Ga, Si, Ge, As, Pb, S, Se, Sn, Bi, F, Cl, Br and I, and
• wherein, when a=1, b=0.01 to 1.0, c=0.01 to 1.0, d=0 to 1 and e is dependent on the oxidation state of the other elements;
• with the proviso that, when d=0, M is selected from the group consisting of Nb and Te, and
• with the further proviso that, when d=0 and M=Te, 0.01≦b<0.50 or
• 0.17<c≦1.0,
• the process comprising:
• (i) admixing compounds of elements Mo, V, M and X, as needed, and a solvent comprising water to form a first admixture containing at least 2 but less than all of said elements Mo, V, M and X;
• (ii) heating said first admixture at a temperature of from 80° C. to 150° C. for from 5 minutes to 48 hours;
• (iii) then, admixing compounds of elements Mo, V, M and X, as needed, with said first admixture to form a second admixture containing elements Mo, V, M and X, in the respective atomic proportions a, b, c and d, wherein, when a=1, b=0.01 to 1.0, c=0.01 to 1.0 and d=0 to 1;
• (iv) heating said second admixture at a temperature of from 50° C. to 300° C. for from 1 hour to several weeks, in a closed vessel under pressure;
• (v) recovering insoluble material from said closed vessel to obtain a catalyst.