# US 4,397,768 A · Supported catalyst for the preparation of phthalic anhydride > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,397,768 A - Document ID: US4397768A - Status: Granted - Kind: A - Application number: 06/325,772 - Filed: 1981-11-30 - Granted: 1983-08-09 - Earliest claimed: 1980-12-01 - Assignees: Oxidaciones Organicas, C.A. "OXIDOR" - Inventors: Klaus M. Felice - Web page: https://patentgrep.com/patent/US4397768A ## CPC - C07C 51/265: having alkyl side chains which are oxidised to carboxyl groups - B01J 23/002: {Mixed oxides other than spinels, e.g. perovskite} - B01J 23/22: Vanadium - B01J 27/198: Vanadium - B01J 2523/00: Constitutive chemical elements of heterogeneous catalysts - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract A catalyst is disclosed comprising an inert carrier supporting a catalytically active mass of vanadium pentoxide, titanium dioxide, promoters and inhibitors for use in the gas phase reaction of ortho-xylene with air to produce phthalic anhydride without addition of sulfur or sulfur dioxide to the ortho-xylene-air mixture. ## Claims ### Claim 1 A catalyst capable of producing phthalic anhydride from o-xylene in the substantial absence of sulfur compounds, consisting essentially of a substantially poreless, mechanically-stable, temperature-resistant, inert carrier to which there is adhered a catalytically active surface coating containing the following components in the following proportions, calculated as the oxides, in relation to one mole of vanadium pentoxide; potassium oxide, from about 0.02 to 0.05 mole; boron trioxide, from about 0.002 to 0.005 mole; antimony trioxide, from about 0.008 to 0.015 mole; and titanium dioxide, from about 10 to 15 moles. ### Claim 2 (depends on 1) A catalyst as claimed in claim 1 wherein the vanadium content calculated as vanadium pentoxide, in the finished catalyst, is from about 0.6 to 1.2 weight percent. ### Claim 3 (depends on 2) A catalyst as in claim 2, where the said surface coating contains up to about 0.01 mole of phosphorus, calculated as P.sub.2 O.sub.5. ### Claim 4 (depends on 2) A catalyst as claimed in claim 2 wherein said inert carrier is selected from among porcelain, steatite, silicon carbide, aluminum, a silicate, an aluminate, and mixtures thereof. ### Claim 5 (depends on 4) A catalyst as claimed in claim 4, in the form of rings, having the dimensions: length from 7.6 mm to 8.0 mm; outer diameter from 8.6 mm to 9.0 mm; and wall thickness from 1.2 mm to 2.3 mm. ### Claim 6 (depends on 1) A catalyst as claimed in claim 1 wherein the catalytically active surface coating, after a five hour heat treatment at 400.degree. C. in an air stream, has a BET surface area of between about 11 and 15 m.sup.2 /g. ### Claim 7 (depends on 1) A process for preparing a catalyst as claimed in claim 1 which comprises air-spraying on to an inert carrier an aqueous suspension consisting essentially of titanium dioxide, vanadium pentoxide, antimony trioxide, boric acid, potassium hydroxide and an organic binder, said suspension having a viscosity of from about 12 to 15 DIN/sec. when measured at 20.degree. C. ### Claim 8 (depends on 7) A process as claimed in claim 7 wherein said air spraying is carried out at an air-stream temperature of from 80.degree. C. to 120.degree. C. ### Claim 9 (depends on 7) A process as claimed in claim 7 wherein the weight ratio of inorganic compounds, expressed as oxides, to said organic binder is from about 3:1 to about 5:1. ### Claim 10 (depends on 9) A process as claimed in claim 9 wherein said organic binder is a copolymer selected from vinylacetate-vinyllaurate, vinylacetate-acrylate, styrene-acrylate, vinylacetate-maleate, or vinylacetate-ethylene. ### Claim 11 (depends on 7) A process as claimed in claim 7 wherein said air-sprayed aqueous suspension is obtained by combining titanium dioxide (anatase) having a BET surface area of between about 12 and 16 m.sup.2 /g, vanadium pentoxide, antimony pentoxide, boric acid, potassium hydroxide, an organic binder and water. ### Claim 12 (depends on 7) A process as claimed in claim 7 wherein said air-sprayed aqueous suspension is obtained by combining titanium dioxide (anatase) as a blend of a titanium dioxide having a BET surface area between about 8 and 10 m.sup.2 /g and a titanium dioxide having a BET surface area between about 15 and 40 m.sup.2 /g, said blend having an average surface area between about 12 and 16 m.sup.2 /g, vanadium pentoxide, antimony pentoxide, boric acid, potassium hydroxide, an organic binder and water. ### Claim 13 (depends on 3) A process for preparing a catalyst as claimed in claim 3 which comprises air-spraying onto an inert carrier an aqueous suspension consisting essentially of titanium dioxide, vanadium pentoxide, antimony trioxide, boric acid, phosphoric acid, potassium hydroxide and an organic binder, said suspension having a viscosity of from about 12 to 15 DIN/sec. when measured at 20.degree. C. ### Claim 14 (depends on 13) A process as claimed in claim 13 wherein said air spraying is carried out at an air-stream temperature of from 80.degree. C. to 120.degree. C. ### Claim 15 (depends on 13) A process as claimed in claim 13 wherein the weight ratio of inorganic compounds, expressed as oxides, to said organic binder is from about 3:1 to about 5:1. ### Claim 16 (depends on 15) A process as claimed in claim 15 wherein said organic binder is a copolymer selected from vinylacetate-vinyllaurate, vinylacetate-acrylate, styrene-acrylate, vinylacetate-maleate or vinylacetate-ethylene. ### Claim 17 (depends on 13) A process as claimed in claim 13 wherein said air-sprayed aqueous suspension is obtained by combining titanium dioxide (anatase) having a BET surface area of between about 12 and 16 m.sup.2 /g, vanadium pentoxide, antimony trioxide, boric acid, phosphoric acid, potassium hydroxide and an organic binder. ### Claim 18 (depends on 13) A process as claimed in claim 13 wherein said air-sprayed aqueous suspension is obtained by combining titanium dioxide (anatase) as a blend of a titanium dioxide having a BET surface area between about 8 and 10 m.sup.2 /g and a titanium dioxide having a BET surface area between about 15 and 40 m.sup.2 /g, said blend having an average surface area between about 12 and 16 m.sup.2 /g, vanadium pentoxide, antimony trioxide, boric acid, phosphoric acid, potassium hydroxide and an organic binder.