Abstract: The present invention relates to a stabilized rhenium-based heterogeneous catalyst, obtainable by a process comprising contacting a rhenium-based heterogeneous catalyst with a stabilizing agent at a temperature in a range from 0-100° C., the stabilizing agent comprising an aliphatic hydrocarbon compound and use thereof.

Abstract: A process for the double-bond isomerization of olefins is disclosed. The process may include contacting a hydrocarbon stream including olefins with a ?-alumina-titania isomerization catalyst to convert at least a portion of the olefin to its positional isomer. The ?-alumina-titania isomerization catalysts disclosed herein may also have the activity to convert alcohol into additional olefins, while having increased resistance to oxygenate poisons.

Abstract: The present invention relates to a diesel oxidation catalyst comprising a carrier substrate, and a first washcoat layer disposed on the substrate, the first washcoat layer comprising palladium supported on a support material comprising a metal oxide, gold supported on a support material comprising a metal oxide, and a ceria comprising compound, as well as a process for the preparation of such catalyst.

Abstract: An exhaust system for a compression ignition engine comprising an oxidation catalyst for treating carbon monoxide (CO) and hydrocarbons (HCs) in exhaust gas from the compression ignition engine, wherein the oxidation catalyst comprises: a platinum group metal (PGM) component selected from the group consisting of a platinum (Pt) component, a palladium (Pd) component and a combination thereof; an alkaline earth metal component; a support material comprising a modified alumina incorporating a heteroatom component; and a substrate, wherein the platinum group metal (PGM) component, the alkaline earth metal component and the support material are disposed on the substrate.

Abstract: A method of making a metal oxide nanoparticle comprising contacting an aqueous solution of a metal salt with an oxidant. The method is safe, environmentally benign, and uses readily available precursors. The size of the nanoparticles, which can be as small as 1 nm or smaller, can be controlled by selecting appropriate conditions. The method is compatible with biologically derived scaffolds, such as virus particles chosen to bind a desired material. The resulting nanoparticles can be porous and provide advantageous properties as a catalyst.

Abstract: A catalyst composition for converting ethanol to higher alcohols, such as butanol, is disclosed. The catalyst composition comprises at least one alkali metal, at least a second metal and a support. The second metal is selected from the group consisting of palladium, platinum, copper, nickel, and cobalt. The support is selected from the group consisting of Al2O3, ZrO2, MgO, TiO2, zeolite, ZnO, and a mixture thereof.

Abstract: Novel photocatalytic devices are disclosed, that utilize ultrathin titania based photocatalytic materials formed on optical elements with high transmissivity, high reflectivity or scattering characteristics, or on high surface area or high porosity open cell materials. The disclosure includes methods to fabricate such devices, including MOCVD and ALD. The disclosure also includes photocatalytic systems that are either standalone or combined with general illumination (lighting) utility, and which may incorporate passive fluid exchange, user configurable photocatalytic optical elements, photocatalytic illumination achieved either by the general illumination light source, dedicated blue or UV light sources, or combinations thereof, and operating methodologies for combined photocatalytic and lighting systems.

Abstract: The present invention relates to a catalyst for Fischer-Tropsch synthesis which has excellent heat transfer capability. This catalyst contains (1) central core particle or particles made of a heat transfer material (HTM) selected from the group consisting of a metal, a metal oxide, a ceramic, and a mixture thereof; and (2) outer particle layer which surrounds the central core particles and is attached to the surfaces of the central core particles by a binder material layer. The outer particle layer has a support and catalyst particles in a powder form containing metal particles disposed on the support. The catalyst having such a dual particle structure shows excellent heat transfer capability and, thus, exhibits high selectivity to a target hydrocarbon. Therefore, the catalyst of the present invention is useful in a fixed-bed reactor for Fischer-Tropsch synthesis for producing hydrocarbons from synthetic gas.

Abstract: The herein disclosed exhaust gas purification catalyst is an exhaust gas purification catalyst that is provided with a porous carrier 40 and palladium 50 supported on this porous carrier 40. The porous carrier 40 is provided with an alumina carrier 42 formed of alumina and with a CZ carrier 44 formed of a ceria-zirconia complex oxide. Barium is added to both the alumina carrier 42 and the CZ carrier 44. Here, an amount of barium added to the alumina carrier 42 is an amount that corresponds to 10 mass % to 15 mass % relative to a total mass of the alumina carrier 42 excluding the barium, and an amount of barium added to the CZ carrier 44 is an amount that corresponds to 5 mass % to 10 mass % relative to a total mass of the CZ carrier 44 excluding the barium.

Abstract: A catalyst composition comprising a vanadate represented by the formula XVO4/S, wherein XVO4 stands for a Bi-, Sb-, Ga- and/or Al-vanadate optionally in mixture with one or more rare earth metal-vanadates, or in mixture with one or more transition metal-vanadates, or in mixture with one or more transition metal-vanadates and one or more rare earth metal-vanadates, and S is a support comprising TiO2, optionally in combination with a dopant and a process for the preparation of such catalyst compositions.

Abstract: The invention concerns a process for the oxidation of organic compounds contained in a gas stream and comprises the step of introducing the gas stream containing the organic compounds together with sufficient oxygen to effect the desired amount of oxidation into an oxidation reactor containing an oxidation catalyst and maintaining the temperature of said gas stream at a temperature sufficient to effect oxidation, characterised in that the oxidation catalyst contains at least 0.01% by weight of ruthenium, cobalt or manganese.

Abstract: The present invention relates to catalysts, to processes for making catalysts and to chemical processes employing such catalysts. The multifunctional catalysts are preferably used for converting acetic acid and ethyl acetate to ethanol. The catalyst is effective for providing an acetic acid conversion greater than 20% and an ethyl acetate conversion greater than 0%. The catalyst comprises a precious metal and one or more active metals on a modified support. The modified support includes a metal selected from the group consisting of tungsten, vanadium, and tantalum, provided that the modified support does not contain phosphorous.

Abstract: Provided are a catalyst for hydrolysis and use of a titanium dioxide-based composition which are capable of removing COS and HCN simultaneously at high degradation percentages. The catalyst for hydrolysis is a catalyst for hydrolysis of carbonyl sulfide and hydrogen cyanide, having at least: an active component containing, as a main component, at least one metal selected from the group consisting of barium, nickel, ruthenium, cobalt, and molybdenum; and a titanium dioxide-based support supporting the active component.

Abstract: The invention provides a polycondensation catalyst for producing polyester by an esterification reaction or a transesterification reaction between a dicarboxylic acid or an ester-forming derivative thereof and a glycol, the polycondensation catalyst being obtained by hydrolyzing a water soluble titanium compound in the absence of a water soluble alkali in an aqueous slurry in which particles of a solid base are dispersed thereby to form on the surface of the particles of the solid base a coat layer of titanic acid in a content of from 0.1 to 50 parts by weight in terms of TiO2 per 100 parts by weight of the solid base. The invention further provides a method for producing the polycondensation catalyst, and polyester obtained using the polycondensation catalyst.

Abstract: A catalyst system comprising a first catalytic composition comprising a first catalytic material disposed on a metal inorganic support; wherein the metal inorganic support has pores; and at least one promoting metal. The catalyst system further comprises a second catalytic composition comprising, (i) a zeolite, or (ii) a first catalytic material disposed on a first substrate, the first catalytic material comprising an element selected from the group consisting of tungsten, titanium, and vanadium. The catalyst system may further comprise a third catalytic composition. The catalyst system may further comprise a delivery system configured to deliver a reductant and optionally a co-reductant. A catalyst system comprising a first catalytic composition, the second catalytic composition, and the third catalytic composition is also provided. An exhaust system comprising the catalyst systems described herein is also provided.

Abstract: A porous oxide catalyst includes porous oxide, and an oxygen vacancy-inducing metal which induces an oxygen vacancy in a lattice structure of a porous metal oxide.

Abstract: The present invention relates to a particle filter comprising a porous carrier body, an SCR active component and an oxidation catalyst, wherein the SCR active component is present as coating on the exhaust-gas entry surface and the inner surface of the porous carrier body and the oxidation catalyst as coating on the exhaust-gas exit surface of the porous carrier body. According to the invention the oxidation catalyst changes its function depending on operating conditions. In normal operation it serves as NH3 slip catalyst for oxidizing excess NH3 and during filter regeneration it operates according to the 3-way principle for converting NOx and CO. The invention also relates to a method for producing the particle filter, the use of the particle filter for treating exhaust gases from the combustion of fossil, synthetic or biofuels as well as an exhaust-gas cleaning system which contains the particle filter according to the invention.

Abstract: Ammonia oxidation catalyst being superior in heat resistance and capable of suppressing by-production of N2O and leakage of ammonia. The ammonia oxidation catalyst (AMOX) removes surplus ammonia, in selectively reducing nitrogen oxides by adding urea or ammonia and using a selective catalytic reduction (SCR) catalyst, into exhaust gas, wherein the ammonia oxidation catalyst is made by coating at least two catalyst layers having a catalyst layer (lower layer) including a catalyst supported a noble metal element on a composite oxide (A) having titania and silica as main components, and a catalyst layer (upper layer) including a composite oxide (C) consisting of tungsten oxide, ceria, and zirconia, at the surface of an integral structure-type substrate, wherein a composition of the composite oxide (C) is tungsten oxide: 1 to 50% by weight, ceria: 1 to 60% by weight, and zirconia: 30 to 90% by weight.

Abstract: The invention relates to a method for producing a catalyst, wherein the catalyst has a high activity and selectivity with regard to the oxidation of CO and NO. The invention also relates to the catalyst produced using the method according to the invention, the use of the catalyst as oxidation catalyst as well as a catalyst component which contains the catalyst according to the invention. Finally, the invention is directed towards an exhaust-gas cleaning system which comprises the catalyst component containing the catalyst according to the invention.

Abstract: Disclosed is an exhaust gas purifying catalyst in which grain growth of a noble metal particle supported on a support is suppressed. Also, disclosed is a production process of an exhaust gas purifying catalyst, by which the above exhaust gas purifying catalyst can be produced. The exhaust gas purifying catalyst comprises a crystalline metal oxide support and a noble metal particle supported on the support, wherein the noble metal particle is epitaxially grown on the support, and wherein the noble metal particle is dispersed and supported on the outer and inner surfaces of the support. The process for producing an exhaust gas purifying catalyst comprises masking, in a solution, at least a part of the surface of a crystalline metal oxide support by a masking agent, introducing the support into a noble metal-containing solution containing a noble metal, and drying and firing the support and the noble metal-containing solution to support the noble metal on the support.

Abstract: Catalyst articles comprising substantially only a palladium precious metal component in a first catalytic layer and a rhodium component in a second catalytic layer and related methods of preparation and use are disclosed. Also disclosed is a catalyst article comprising a first layer formed on a carrier substrate, wherein the first layer comprises a refractory metal oxide and has a surface that is substantially uniform; a second layer formed on the first layer, wherein the second layer comprises i) an oxygen storage component that is about 50-90% by weight of the second layer and ii) a palladium component in an amount of about 2-5% by weight of the second layer, wherein the palladium component is substantially the only platinum group metal component, and a palladium-free third layer comprising a rhodium component supported on a thermostable oxygen storage component which is about 80-99% by weight of the second layer. One or more improved properties are exhibited by the catalyst article.

Abstract: Catalyst articles comprising palladium and related methods of preparation and use are disclosed. Disclosed is a catalyst article comprising a first catalytic layer formed on a substrate, wherein the first catalytic layer comprises palladium impregnated on a ceria-free oxygen storage component and platinum impregnated on a refractory metal oxide, and a second catalytic layer formed on the first catalytic layer comprising platinum and rhodium impregnated on a ceria-containing oxygen storage component. The palladium component of the catalyst article is present in a higher proportion relative to the other platinum group metal components. The catalyst articles provide improved conversion of carbon monoxide in exhaust gases, particularly under rich engine operating conditions.

Abstract: The exhaust gas purification catalyst according to the present invention has a substrate 54, a lower layer 57 disposed on this substrate 54, and an upper layer 58 disposed on this lower layer 57. The upper layer 58 is provided with a first catalyst and a second catalyst, and the lower layer 57 is provided with a first catalyst. This first catalyst has Al2O3 as a carrier and Pt and Pd as noble metals supported on the Al2O3, while the second catalyst typically has an Al2O3—ZrO2—TiO2 complex oxide as a carrier and has Pd as a noble metal supported on the Al2O3—ZrO2—TiO2 complex oxide. Moreover, the upper layer 58 has a hydrocarbon adsorbent 68.

Abstract: The invention relates to a filtration structure, for filtering a gas coming from a diesel engine, which is laden with gaseous pollutants of the nitrogen oxide NOx type and with solid particles, of the particulate filter type, said filtration structure being characterized in that it includes a catalytic system comprising at least one noble metal or transition metal suitable for reducing the NOx and a support material, in which said support material comprises or is made of a zirconium oxide partially substituted with a trivalent cation M3+ or with a divalent cation M?2+, said zirconium oxide being in a reduced, oxygen-sub-stoichiometric, state.

Abstract: A catalyst for purification of exhaust gas, in which a noble metal is supported on a metal oxide support, has a basic site content of 1 mmol/L-cat or less, as determined on the basis of an amount of CO2 desorbed per liter of the catalyst as measured by a CO2 temperature-programmed desorption method.

Abstract: The invention relates to the use of a catalytic composition for selective methanization of carbon monoxide in hydrogen- and carbon dioxide-containing streams, wherein the active component used is ruthenium and the support material is a lanthanum-cerium-zirconium oxide, where the total loading of the support material with the active component is 0.1 to 20% by weight, based on the total weight of the catalytically active composition, and the support material comprises a lanthanum oxide content of 0.1 to 15% by weight, a cerium oxide content of 0.1 to 15% by weight and a zirconium oxide content of 30 to 99.8% by weight, based on the weight of the overall support material.

Abstract: Provided is a method for manufacturing a titania coated alumina fiber aggregate which includes the steps of: forming an aluminum fiber aggregate where aluminum fibers are aggregated with density per unit volume of 0.5 g/cm3 to 3 g/cm3; forming an alumina fiber aggregate where an oxide film having a film thickness of 50 nm or more is formed on alumina fibers; and forming a titania coated alumina fiber aggregate where a titania thin film is formed on alumina fibers.

Abstract: An Object of the patent is to remove highly reducing hydrocarbon exhausted during acceleration period, and to remove efficiently hydrocarbon even after contacting with highly reducing hydrocarbon. By using a catalyst having a higher proportion of palladium having surface charge of 2-valence or 4-valence supported than that of 0-valence by supporting palladium together with magnesium oxide, hydrocarbon exhausted from an internal combustion engine especially during acceleration period can be efficiently removed.

Abstract: A catalyst for the manufacture of alkylene oxide, for example ethylene oxide, by the vapor-phase epoxidation of alkene containing impregnated silver and at least one efficiency-enhancing promoter on an inert, refractory solid support, said support incorporating a sufficient amount of zirconium component (present and remaining substantially as zirconium silicate) as to enhance at least one of catalyst activity, efficiency and stability as compared to a similar catalyst which does not contain the zirconium component.

Abstract: A NOx storage component comprises caesium silicate (Cs2SiO3) and at least one platinum group metal. The invention also includes a NOx absorber catalyst comprising a NOx storage component according to the invention disposed on a substrate monolith; a method of treating exhaust gas containing NOx from a lean burn internal combustion engine comprising the steps of contacting a NOx storage component comprising caesium silicate (Cs2SiO3) and at least one platinum group metal with lean exhaust gas containing NOx to adsorb NOx thereon; and periodically desorbing adsorbed NOx by contacting the NOx storage component with stoichiometric or rich exhaust gas; and a method of making a NOx storage component according to the invention comprising the steps of combining and reacting an aqueous salt of at least one platinum group metal, an aqueous caesium salt and a source of silica.

Abstract: Described is a nitrogen oxide storage catalyst comprising: a substrate; a first washcoat layer provided on the substrate, the first washcoat layer comprising a nitrogen oxide storage material, a second washcoat layer provided on the first washcoat layer, the second washcoat layer comprising a hydrocarbon trap material, wherein the hydrocarbon trap material comprises substantially no element or compound in a state in which it is capable of catalyzing selective catalytic reduction, preferably wherein the hydrocarbon trap material comprises substantially no element or compound in a state in which it is capable of catalyzing a reaction wherein nitrogen oxide is reduced to N2, said catalyst further comprising a nitrogen oxide conversion material which is either comprised in the second washcoat layer and/or in a washcoat layer provided between the first washcoat layer and the second washcoat layer.

Abstract: The present invention relates to a photocatalytic material having a visible light activity which includes a tungsten-doped titanium oxide or a tungsten/gallium-codoped titanium oxide, and a divalent copper salt and/or a trivalent iron salt supported on a surface of the doped or codoped titanium oxide, and a process for producing the photocatalytic material.

Abstract: The present invention provides a catalyst comprising a catalytic metal, preferably cobalt, rhenium or mixtures thereof. The catalytic metal is supported on a support comprising a major amount of titania and a minor amount of cobalt aluminate derived from anatase titania. The support also includes a minor amount of titania derived from a titanium chelate.

Abstract: A method for providing a catalyst on a substrate is disclosed comprising providing a first washcoat comprising a soluble washcoat salt species, a polar organic solvent, and an insoluble particulate material, contacting the first washcoat with a substrate to form a coated substrate, and then contacting the coated substrate with a second washcoat comprising an oxide or an oxide-supported catalyst to physisorb, chemisorb, bond, or otherwise adhere the oxide or the oxide-supported catalyst to the coated substrate. Also disclosed is a catalyst on a substrate comprising: a substrate; an anchor layer comprising a soluble washcoat salt species, a polar organic solvent, and an insoluble particulate material; and a second layer comprises an oxide or an oxide-supported catalyst. The catalyst on a substrate can be in either green or fired form.

Abstract: The invention provides a polycondensation catalyst for producing polyester by an esterification reaction or a transesterification reaction between a dicarboxylic acid or an ester-forming derivative thereof and a glycol, wherein the polycondensation catalyst comprises particles of a solid base having on the surfaces an inner coating layer of titanic acid in an amount of from 0.1 to 50 parts by weight in terms of TiO2 per 100 parts by weight of the solid base, and an outer coating layer either of an oxide of at least one element selected from aluminum, zirconium and silicon, or of a composite oxide of at least two elements selected from aluminum, zirconium and silicon on the surface of the inner coating layer in an amount of from 1 to 50 parts by weight per 100 parts by weight of the solid base.

Abstract: A bulk metal oxide catalyst composition of the general formula (X)b(M)c(Z)d(O)e??(I) wherein X represents at least one non-noble Group VIII metal; M represents at least one non-noble Group VIb metal; Z represents one or more elements selected from aluminum, silicon, magnesium, titanium, zirconium, boron, and zinc; one of b and c is the integer 1; and d and e and the other of b and c each are a number greater than 0 such that the molar ratio of b:c is in the range of from 0.5:1 to 5:1, the molar ratio of d:c is in the range of from 0.2:1 to 50:1, and the molar ratio of e:c is in the range of from 3.7:1 to 108:1; is prepared by controlled (co)precipitation of component metal compounds, refractory oxide material, and alkali compound in protic liquid. Resulting compositions find use in hydrotreatment processes involving particularly hydrodesulphurization and hydrodenitrification.

Abstract: A mesoporous oxide-catalyst complex including: a mesoporous metal oxide; and a catalyst metal supported on the mesoporous metal oxide, wherein the catalyst on the mesoporous metal oxide has a degree of dispersion of about 30 to about 90 percent.

Abstract: Catalyst compositions include finely divided nanoscale particles of at least one supported oxide selected from among zirconium oxide, titanium oxide or a mixed zirconium/titanium oxide deposited onto an alumina-based or aluminum-oxyhydroxide-based support, wherein, after calcination for 4 hours at 900° C., the at least one support oxide is in the form of nanoscale particles deposited onto the support, the size of said particles being at most 10 nm when the at least one supported oxide is based is zirconium oxide and being at most 15 nm when the at least one supported oxide is titanium oxide or a mixed zirconium/titanium oxide; such catalyst compositions are especially useful for the selective reduction of NOx.

Abstract: The present invention relates to a catalyst combination for hydrotreating raw oils and a process for hydrotreating raw oils with the catalyst combination. The catalyst combination comprises one or both of at least one hydrogenation protection catalyst I and at least one hydrogenation demetalling catalyst I; at least one hydrogenation demetalling catalyst II; and at least one hydrogenation treatment catalyst III.

Abstract: A catalyst for removal of NOx from exhaust gas, containing cerium oxide and titanium dioxide, wherein a first portion of the cerium oxide forms at least one agglomerate of cerium oxide crystallites interdispersed in the titanium dioxide, and a second portion of the cerium oxide forms at least one island on a surface of the titanium dioxide, a method for producing the catalyst, a process for selectively reducing NOx levels in an exhaust gas using the catalyst, and an SCR canister containing the catalyst therein.

Abstract: A catalyst of one or more complex oxides having a nominal composition as set out in formula (1): AxB1-y-zMyPzOn (1) wherein A is selected from one or more group III elements including the lanthanide elements or one or more divalent or monovalent cations; B is selected from one or more elements with atomic number 22 to 24, 40 to 42 and 72 to 75; M is selected from one or more elements with atomic number 25 to 30; P is selected from one or more elements with atomic number 44 to 50 and 76 to 83; x is defined as a number where 0<x?1; y is defined as a number where 0?y<0.5; and z is defined as a number where 0<z<0.2.

Abstract: The present invention relates to a method for producing a precursor of a supported platinum catalyst. To provide a method for producing a platinum catalyst precursor, by means of which supported platinum catalysts can be produced which have a relatively high activity, a method is proposed, comprising the steps of: a) impregnating an open-pored support material with platinum sulphite acid; b) calcining the impregnated zeolite material under a protective gas.

Abstract: The present invention provides catalyst compositions useful for transamination reactions. The catalyst compositions have a catalyst support that includes transitional alumina, use a low metal loading (for example, less than 25 wt. %), and do not require the presence of rhenium. The catalyst compositions are able to advantageously promote transamination of a reactant product (such as the transamination of EDA to DETA) with excellent activity and selectivity, and similar to transaminations promoted using a precious metal-containing catalyst.

Abstract: A series of binary and ternary Pt-alloys, that promote the important reactions for catalysis at an alloy surface; oxygen reduction, hydrogen oxidation, and hydrogen and oxygen evolution. The first two of these reactions are essential when applying the alloy for use in a PEMFC.

Abstract: Disclosed are tunable catalysts and methods of controlling the activity of a catalyst. For example, disclosed are methods of controlling the activity of a catalyst, comprising providing a catalyst, comprising a ferroelectric substrate of finite thickness comprising two opposing surfaces, the ferroelectric substrate being characterized as having a polarization; an electrode surmounting one of the surfaces of the ferroelectric substrate; and a catalytically active material surmounting the surface of the ferroelectric substrate opposing the electrode; and subjecting the ferroelectric substrate to a controllable electric field to give rise to a modulation of the polarization of the ferroelectric substrate, whereby the modulation of the polarization controllably alters the activity of one or more chemical species on the catalytically active material.

Abstract: A shell catalyst for producing vinyl acetate monomer (VAM), comprising an oxidic porous catalyst support, formed as a shaped body, with an outer shell in which metallic Pd and Au are contained. To provide a shell catalyst for producing VAM which has a relatively high activity and can be obtained at relatively low cost, the catalyst support is doped with at least one oxide of an element selected from the group consisting of Li, P, Ca, V, Cr, Mn, Fe, Sr, Nb, Ta, W, La and the rare-earth metals.

Abstract: According to various embodiments, a catalyst composition includes a catalytic metal secured to a porous substrate. The substrate has pores that are templated. The substrate is a product of adding a substrate precursor to a water-in-oil microemulsion including a catalytic metal salt, a solvent, a templating agent, and water.

Abstract: A device is described which provides thermally durable NO2 generation in conjunction with efficient heat-up performance for filter regeneration, and low temperature HC (hydrocarbon) and CO activity. Importantly, it provides both functions while minimizing PGM (platinum group metals) utilization and its associated impact on catalyst cost.

Abstract: Methods are described for making a texturized catalyst. The textural promoter may be a high-surface area, high-porosity, stable metal oxide support. The catalyst is manufactured by reacting catalyst precursor materials and support materials in a single, solvent deficient reaction to form a catalyst. The catalyst may be particles or a coating or partial coating of a support surface.

Abstract: The invention relates to a porous structure comprising a ceramic material comprising mainly or consisting of an oxide material of the pseudobrookite type comprising titanium, aluminum, magnesium and zirconium in proportions such that the phase of the pseudobrookite type substantially satisfies the formula: (Al2TiO5)x(MgTi2O5)y(MgTiZrO5)z. This material satisfies the following composition, in mol % on the basis of just the oxides Al2O3, TiO2, MgO and ZrO2: 90<2a+3m<110; 100+a<3t<210?a; and a+t+m+zr=100, in which: a is the molar content of Al2O3; t is the molar content of TiO2; m is the molar content of MgO; and zr is the molar content of ZrO2.