Solid catalysts suited for the fluidized/moving bed catalytic ammoxidation of alkanes comprise an active catalytic phase having the empirical formula (I): VSbaSnbTicFedEeOx  (I) in which E is an element which provides an oxide of rutile structure or an element which, in combination with V, Sb, Sn, Ti, Fe and/or with another element E, provides a phase of rutile or trirutile structure, or a solid solution of rutile structure, a is a whole or fractional number equal to or greater than 0.5, b, c, d and e, independently, are each a whole or fractional number ranging from 0 to 100, and x is a whole or fractional number determined by the oxidation state of the other elements, such active catalytic phase being deposited onto/into particulates of a solid and porous oxidic support therefor, and are produced by (a) impregnating the solid and porous oxidic support with a solution, in at least one saturated alcohol, of compounds of vanadium and antimony and, optionally, compounds of tin and/or titanium and/or of iron and/or of element E, (b) contacting the solid and porous oxidic support thus impregnated with an aqueous buffer solution having a pH ranging from about 6 to 8, (c) separating the solids from such aqueous buffer solution and drying same, and (d) calcining the dried solids in two stages.