Disclosed is a method for preparing a solid material including manganese, the method including the following steps: a. bringing into contact an aqueous effluent including manganese, for example at least 5 mg/L, typically at least 5 to 50 mg/L, and preferably 7 to 25 mg/L of manganese, with an oxidizing agent, manganese, preferably at a temperature between 10° C. and 50° C., and obtaining an oxidized aqueous solution; b. adding a base to the oxidized aqueous solution obtained at the end of step a) until a pH of between 8 and 12, preferably greater than 9, and preferably from 9 to 10.5, and obtaining a solution including a precipitate; c. filtration of the solution obtained at the end of step b); and d. obtaining a solid material including manganese, and especially manganese (IV) and/or Mn (III).

A catalytic bed for the partial oxidation of n-butane to maleic anhydride which comprises at least one first catalytic layer and at least one second catalytic layer, wherein each catalytic layer consists of a vanadium and phosphorus mixed oxide (VPO) catalyst and only the catalyst of the second catalytic layer further comprises tungsten, and wherein the second catalytic layer constitutes 25% to 45% of the total length of the catalytic bed and is arranged consecutively after the first catalytic layer along the direction in which the mixture of gases comprising the oxidation reagents flows. The present invention also relates to a process for producing maleic anhydride by partial oxidation of n-butane which uses the catalytic bed.

Provided is a composition comprising alumina, the alumina being surface-modified with a perovskite type compound of formula (I); wherein formula (I) is defined by A.sub.x-yA′.sub.yB.sub.1. .sub.zB′.sub.zO.sub.3; where: A is an ion of a metal selected from the group consisting of Li, Na, K, Cs, Mg, Sr, Ba, Ca, Y, La, Ce, Pr, Nd, and Gd; A′ is an ion of a metal selected from the group consisting of Li, Na, K, Cs, Mg, Sr, Ba, Ca, Y, La, Ce, Pr, Nd, and Gd; B is an ion of a metal selected from the group consisting of Cu, Mn, Mo, Co, Fe, Ni, Cr, Ti, Zr, Al, Ga, Sc, Nb, V, W, Bi, Zn, Sn, Pt, Rh, Pd, Ru, Au, Ag, and Ir; B′ is an ion of a metal selected from the group consisting of Cu, Mn, Mo, Co, Fe, Ni, Cr, Ti, Zr, Al, Ga, Sc, Nb, V, W, Bi, Zn, Sn, Pt, Rh, Pd, Ru, Au, Ag, and Ir; x is from 0.7 to 1; y is from 0 to 0.5; and z is from 0 to 0.5.

A precursor mixture for producing a porous body, wherein the precursor mixture comprises: (i) milled alpha alumina powder having a particle size of 0.1 to 6 microns, (ii) boehmite powder that functions as a binder of the alpha alumina powders, and (iii) burnout materials having a particle sizes of 1-10 microns. In some embodiments, an unmilled alpha alumina powder having a particle size of 10 to 100 microns is also included in said precursor mixture. Also described herein is a method for producing a porous body in which the above-described precursor mixture is formed to a given shape, and subjected to a heat treatment step in which the formed shape is sintered to produce the porous body.

According to the subject matter of the present disclosure, a method of producing an aromatization catalyst may comprise producing a plurality of uncalcined ZSM-5 nanoparticles via a dry-gel method, directly mixing the plurality of uncalcined ZSM-5 nanoparticles with large pore alumina and a binder to form a ZSM-5/alumina mixture, and calcining the ZSM-5/alumina mixture to form the aromatization catalyst. The plurality of uncalcined ZSM-5 nanoparticles may have an average diameter of less than 80 nm.

A method of preparing a catalyst comprising a) contacting a non-aqueous solvent, a carboxylic acid, and a chromium-containing compound to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst. A method of preparing a catalyst comprising a) contacting a non-aqueous solvent and a carboxylic acid to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed chrominated silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst.

An oxidation catalyst for treating an exhaust gas from a diesel engine comprises: a first washcoat region for oxidising carbon monoxide (CO) and hydrocarbons (HCs), wherein the first washcoat region comprises a first platinum group metal (PGM) and a first support material, and wherein the first washcoat region does not comprise manganese or an oxide thereof; a second washcoat region for oxidising nitric oxide (NO), wherein the second washcoat region comprises platinum (Pt), manganese (Mn) and a second support material comprising a refractory metal oxide, which is silica-alumina or alumina doped with silica in a total amount of 0.5 to 45% by weight of the alumina, wherein the platinum (Pt) is disposed or supported on the second support material and the manganese (Mn) is disposed or supported on the second support material; and a substrate having an inlet end and an outlet end, and wherein the first washcoat region is a first washcoat layer and the second washcoat region is a second washcoat layer, and the second washcoat layer is disposed on the first washcoat layer; and wherein when the oxidation catalyst comprises a hydrocarbon adsorbent, which is a zeolite, then the first washcoat region further comprises the hydrocarbon adsorbent.

A method for the manufacture of an oxygen reduction reaction (ORR) catalyst, the method comprising; providing a metal organic framework (MOF) material having a specific internal pore volume of 0.7 cm.sup.3g.sup.−1 or greater; providing a source of iron and/or cobalt; pyrolysing the MOF material together with the source of iron and/or cobalt to form the catalyst, wherein the MOF material comprises nitrogen and/or the MOF material is pyrolysed together with a source of nitrogen and the source of iron and/or cobalt is disclosed.

The invention relates to a composite oxide comprising CaO stabilised by Ca.sub.3Al.sub.2O.sub.6 (C3A), wherein the composite is in the form of particles. The mixed oxide composite is useful as a catalyst in the transesterification of triglycerides, e.g. in the production of biodiesel. Calcium leaching is more hindered in CaO—Ca.sub.3Al.sub.2O.sub.6 (2Ca/Al) than in CaO—Al.sub.2O.sub.3.

The invention relates to a method of preparing titanium dioxide-coated nanostars. Titanium precursors are hydrolyzed into crystalline TiO.sub.2 polymorphs at low temperatures, allowing the delicate morphology of the nanostars to be preserved while maintaining their desirable photocatalytic properties.