US 4,709,071 A · Process for improving activity of tellurium containing metal oxide catalysts

Abstract

A process for improving the activity of tellurium containing metal oxide catalysts useful as catalysts for oxidation, ammoxidation or oxidative dehydrogenation of organic compounds by heating the catalysts together with a tellurium containing solid and an optional molybdenum containing solid to a temperature up to about 900.degree. C. in a gaseous atmosphere. The process can be effectively applied to deteriorated or spent catalysts, the activity of which has been deteriorated due to use for a long period of time. The tellurium containing solid used as an activity improving agent is elemental tellurium and the molybdenum containing solid is selected from the group consisting of (i) a molybdenum compound, (ii) at least one molybdenum compound supported on an inert carrier, and (iii) a molybdenum enriched catalyst prepared by adding a Mo component to a metal oxide catalyst (which may be a fresh catalyst or a deteriorated catalyst). In a particularly preferred embodiment, the process for improving the activity according to the present invention can be carried out by contacting the deteriorated tellurium containing metal oxide catalyst with the elemental tellurium and optional molybdenum-containing solid in a fluidized-bed. More preferably, the contact is carried out during the oxidation, ammoxidation or oxidative dehydrogenation reaction.

Claims17

Dependent claims

In the process for the production of nitriles by the ammoxidation reaction of hydrocarbons or alcohols at a temperature of about 300.degree. C. to about 600.degree. C. in a fluidized-bed reactor using a tellurium-containing metal oxide catalyst (A) having a composition, as defined in a freshly prepared state, represented by an empirical formula,

Sb.sub.a.sbsb.1 Mo.sub.a.sbsb.2 V.sub.a.sbsb.3 Te.sub.b C.sub.c D.sub.d E.sub.e O.sub.x
wherein Te represents tellurium, C represents at least one element selected from the group consisting of B, P, As, Bi, S and Se, D represents at least one element selected from the group consisting of Li, Na, K, Rb, Cs and Tl, E represents at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Y, La, Ce, U, Ti, Zr, Nb, Ta, Cr, W, Mn, Re, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu, Ag, Zn, Cd, Al, Ga, In, Ge, Sn and Pb, and O represents Oxygen;
and a, b, c, d, e and x represent the atomic ratios of the elements in the formula for which they are subscripts, where a.sub.1 +a.sub.2 +a.sub.3 =10, 0<a.sub.1 +a.sub.2 .ltoreq.10 and 0.ltoreq.a.sub.3 <10, b=0.01 to 5, c=0 to 10, d=0 to 5, e=0 to 60 and x is the number of oxygen corresponding to the oxides formed by combining the above described components, said catalyst has become partially deactivated during the reaction, the process comprising regenerating the deactivated catalyst at the reaction temperature by contacting the deactivated catalyst with an activity improving agent comprising elemental tellurium while conducting the reaction.

In the process for the production of nitriles by the ammoxidation reaction of hydrocarbons or alcohols at a temperature of about 300.degree. C. to about 600.degree. C. in a fluidized-bed reaction using a metal oxide catalyst (A) having a composition, as defined in a freshly prepared state, represented by an empirical formula,

Sb.sub.a.sbsb.1 Mo.sub.a.sbsb.2 V.sub.a.sbsb.3 Te.sub.b C.sub.c D.sub.d E.sub.e O.sub.x
wherein Te represents tellurium, C represents at least one element selected from the group consisting of B, P, As, Bi, S and Se, D represents at least one element selected from the group consisting of Li, Na, K, Rb, Cs and Tl, E represents at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Y, La, Ce, U, Ti, Zr, Nb, Ta, Cr, W, Mn, Re, Fe, Co, Ni, Ru, Pd, Os, Ir, Pt, Cu, Ag, Zn, Cd, Al, Ga, In, Ge, Sn and Pb, and O represents oxygen;
and a, b, c, d, e and x each represents the atomic ratio of the elements in the formula for which they are subscripts, wherein a.sub.1 +a.sub.2 +a.sub.3 =10, 0<a.sub.1 +a.sub.2 .ltoreq.10 and 0.ltoreq.a.sub.3 <10, b=0.01 to 5, c=0 to 10, d=0 to 5, e=0 to 60 and x is the number of oxygen corresponding to the oxides formed by combining the above described components, said catalyst has become partially deactivated during the reaction, the process comprising regenerating the deactivated catalyst at the reaction temperature by contacting the deactivated catalyst with an activity improving agent comprising (1) elemental tellurium and (2) a molybdenum containing material selected from the group consisting of (i) a molybdenum compound not supported on an inert carrier, (ii) a molybdenum enriched metal oxide catalyst having the empirical formula as catalyst (A) above but with a molybdenum content increased by 0.5% by weight or more and (iii) a molybdenum compound supported on an inert carrier, while conducting the reaction.

Dependencies are inferred from the claim text.

Process for improving activity of tellurium containing metal oxide catalysts

Life of this patent

Process for improving activity of tellurium containing metal oxide catalysts

Life of this patent

Abstract

Claims17