Koppers Company, Inc.

Philip H Harju

Eugene A Pasek

Kenneth R Call

The invention discloses a method of impregnating a porous catalyst carrier with a partially hydrolyzed aqueous methanol solution of titanium tetrachloride, and completing the hydrolysis to titanium dioxide under controlled conditions of temperature and by-product removal to obtain the desired anatase, rutile or combination anatase/rutile polymorphic form of titanium dioxide.

Preparation of crystalline TiO.sub.2 as anatase and/or rutile in porous

Catalytic material is provided by a composition comprising the elements vanadium, non-water-contained hydrogen, phosphorus and non-water-contained oxygen. Freshly prepared catalytic material proxides relatively high yields upon its initial use in the catalytic oxidation of hydrocarbon feedstocks, such as n-butane and benzene to maleic anhydride.

Fluid-bed catalysts process for making maleic anhydride

Catalytic material is prepared by impregnating porous silica with an aqueous solution containing vanadyl oxalate (VOC.sub.2 O.sub.4), potassium sulfate (K.sub.2 SO.sub.4) and potassium bisulfate (KHSO.sub.4). A free-flowing dry-appearing powder is provided comprising particles having substantially all compounds deposited from the impregnating solution attached to the silica particles within pores of the particles. Subsequent calcining of the powder provides a mixture of compounds within the particle pores containing at least one oxide of vanadium and at least one sulfate of potassium. Catalytic material prepared by the disclosed process is characterized in having a substantially uniform concentration of deposited compounds within the pores of the silica support. The catalytic material is particularly useful in a process for fluid bed oxidation of naphthalene to phthalic anhydride, in which oxidation process the catalyst provides high product yield at a low catalyst attrition rate.

Preparation of naphthalene-oxidation catalyst by impregnation of silica

Catalytic material is provided by a composition comprising the elements vanadium, non-water-contained hydrogen, phosphorus and non-water-contained oxygen. The VHPO elements are present in a relatively fixed atomic ratio range, there being more non-water-contained oxygen present than phosphorus by an atomic ratio of greater than five to one. The catalytic material comprises an anhydrous primary component having vanadium of mixed valence, hydrogen, phosphorus and oxygen in an empirical relationship defined by VH.sub.x PO.sub.y, wherein 'x' has an average value in a range from about 1.29 to about 1.40, and 'y' has an average value in a range from about 5.46 to about 5.55. The anhydrous VHPO catalytic material may also be described by a structural formula (VO).sub.m (VO.sub.2).sub.n H.sub.2n (PO.sub.4).sub.n (P.sub.2 O.sub.7).sub.m/2, wherein m+n=3, 'm' has an average value in a range from about 0.90 to about 1.07, and 'n' has an average value in a range from about 1.93 to about 2.10. The primary component is mostly amorphous and in its substantially anhydrous form is characterized by a powder X-ray diffraction pattern having broad peaks with CuK.alpha. d-spacings of 4.30, 4.17 and 3.09 A. The catalytic material is prepared by a process comprising the steps of reducing vanadium pentoxide with a reducing agent in an aqueous solution of phosphoric acid, followed by the step of oxidizing a portion of the vanadium species with an oxidizing agent to form a slurry of a precipitate containing vanadium(IV) and vanadium(V) in contact with a water solution containing vanadium(IV).

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Spring Church, PA, United States of America

Philip H Harju