117results about How to "Good catalytic activity" patented technology

According to the present invention, there is provided a honeycomb catalytic structure comprising:a honeycomb structure comprising porous partition walls having a large number of pores, disposed so as to form a plurality of cells extending between the two end faces of the honeycomb structure and plugging portions disposed at either one end of each cell, anda catalyst layer containing a catalyst, supported at least on the inner surfaces of the pores of the honeycomb structure,wherein the mass of the catalyst layer per unit volume (1 cm3) of the honeycomb structure (g / cm3) is 60% or less of the volume of pores per unit volume (1 cm3) of the honeycomb structure (cm3 / cm3).

The invention provides a preparation method of a Cu-SSZ-13 molecular sieve based catalyst. The preparation method comprises the following steps of adding sodium aluminate, sodium hydroxide, a silica solution, copper sulfate, tetraethylenepentamine and an organic template agent to deionized water, and performing stirring so as to obtain gel; and performing a reaction in a reaction kettle, then performing cooling, performing centrifugal filtration, performing washing, performing drying, and performing calcining so as to obtain the Cu-SSZ-13 molecular sieve based catalyst. The method disclosed by the invention is simple in technology, low in cost, energy-saving, and environmentally-friendly. Use of a copper salt solution ion exchange and calcining technology many times is avoided, and the defect that a conventional technology needs performing later-period ion exchange so as to reduce content of active components is overcome. The silica alumina ratio of the Cu-SSZ-13 molecular sieve based catalyst prepared by the method disclosed by the invention is adjustable within the range of 7.9- 26.7, and the percentage by mass of copper is in the range of 0.47 -8.6wt%, excellent NH3-SCR catalytic activity, water thermal stability, alkali metal poisoning resistance and noble metal poisoning resistance can be kept in a wide-temperature window.

The invention relates to application of nanometer cobaltosic oxide (Co3O4) used as a peroxide enzyme mimic for measuring the concentration of hydrogen peroxide; nanometer cobaltosic oxide used as the peroxide enzyme mimic has peroxidase-like activity, and further comprises various sizes of nanometer cobaltosic oxide particles; the particle diameter of nanometer cobaltosic oxide exceeds 9 nm; a cobaltosic oxide nanometer material can be used for catalyzing degradation of a phenolic substance, and has potential for being applied to printing and dyeing wastewater treatment. According to the application provided by the invention, the peroxide enzyme mimic function of nanometer cobaltosic oxide is found for the first time, so that nanometer cobaltosic oxide can be used as the peroxide enzyme mimic for measuring the content of hydrogen peroxide; compared with HRP, nanometer cobaltosic oxide used as a catalyst is higher in stability and reusability, and more efficient in peroxide enzyme mimic catalytic activity; without the presence of hydrogen peroxide, nanometer cobaltosic oxide can also be used for catalyzing color developing agents, and used as an enzyme mimic.

The invention discloses a novel disulfonate type alkyl imidazole ionic liquid as well as a preparation method and application thereof. Structure of the ionic liquid is shown as formula (I), and the preparation method of the ionic liquid comprises the followings steps: trimethylsilylimidazole with structure shown as formula (II) is dropwise added to sultones with the structure shown as formula (III) for heat insulation reaction at the temperature of minus 20 DEG C to 30 DEG C, then water is dropwise added for continuing the heat insulation reaction to obtain an intermediate product (a zwitterionic compound) with the structure shown as formula (IV); an HY acid is dropwise added to aqueous solution of the zwitterionic compound to obtain a target product after full reaction at the temperature of 60-100 DEG C. The designed ionic liquid is hydrostable, almost has no steam pressure, especially has strong acidic properties, exhibits good catalytic activity when being applied to pechmann reaction, and a synthetic method thereof has environment-friendly feature, thus being expected to be applied to organic synthesis and catalysis fields as an environment-friendly solvent and catalyst.

The invention provides a preparation method for synthesizing a Cu-SSZ-39 molecular sieve based catalyst by using a one-step method and application. By using the one-step method, the Cu-SSZ-39 molecular sieve based catalyst is synthesized through a double template; the copper load is controlled at 2.00-5.00 wt.% by controlling the input ratio of copper sulfate-tetraethylenepentamine to the organic template; and meanwhile, the silica-alumina ratio of USY is controlled to reach the silica-alumina ratio of 4.5-16.4 in the controlled product so that the Cu-SSZ-39 molecular sieve based catalyst with higher degree of crystallization, excellent catalytic activity and hydrothermal stability; and the Cu-SSZ-39 molecular sieve based catalyst is suitable for the nitrogen oxide purification processes in diesel vehicle aftertreatment Urea-SCR system catalysts and fixed sources NH3-SCR. Compared with the existing synthetic method, the preparation method for synthesizing the Cu-SSZ-39 molecular sieve based catalyst by using the one-step method, provided by the invention, has the advantages that the process is simple, repeated uses of an ammonium nitrate and copper salt solution ion exchanging and calcining process are avoided, and a defect that the traditional one-step synthetic method can only load an active component through the later ion exchanging process is overcome. By using the cheap template, the preparation method for synthesizing the Cu-SSZ-39 molecular sieve based catalyst by using the one-step method greatly reduces the production cost and is beneficial for industrial amplification applications.

The invention relates to a sulfonic acid dual-core ion liquid catalyst and a method using the same for synthesizing polydiethylene glycol sebacate. The structure of the catalyst is shown in the specification, wherein R is CH2CH2CH2 or CH2CH2CH2CH2, and n is equal to 2-8. In the invention, sulfonic acid dual-core ion liquid catalyst is utilized to synthesize the polydiethylene glycol sebacate, therefore, the problems that in the prior art, PBS molecular weight is not high, the color phase is poor and the like are solved. By utilizing the catalyst, the molecular weight of the polydiethylene glycol sebacate obtained by catalytic catalysis is high, the viscosity-average molecular weight can reach 1.0*10<5>-1.5*10<5>, the breaking strength reaches 35-55MPa, and the breaking elongation is 200%-420%. In the invention, the viscosity-average molecular weight of the PBS is improved greatly; therefore, the application value of the catalyst is improved.

The invention provides a nickel-cobalt-phosphorus crystal, and a preparation method and an application thereof. The nickel-cobalt-phosphorus crystal prepared through controlling the proportions of elements in nickel-cobalt-phosphorus, the morphology and the dimension has very good catalysis activity in water electrolysis as a water electrolysis catalyst. According to the embodiment in the invention, the nickel-cobalt-phosphorus crystal has similar catalysis activity to commercial platinized carbon electrodes as a water electrolysis catalyst, can be used in electrocatalytic hydrogen evolution and oxygen production, has a stable catalysis performance and has very good industrial application prospect. Compared with traditional high temperature solid phase reaction, the nickel-cobalt-phosphorus crystal preparation method provided by the invention has the advantages of simple operating process, mild synthesis conditions, easy control of the product morphology, great shortening of the growth time of the synthesized nickel-cobalt-phosphorus crystal, reduction of the reaction temperature, energy consumption saving, high product yield, low cost and large-scale industrial production.

The invention belongs to the technical field of environmental protection, and in particular, relates to preparation and application of a supported zirconium-based metal organic skeleton catalyst PTA@UiO-66 synthesized by an in-situ hydrothermal method. Because the molecular diameter of phosphotungstic acid (1.2 nm) is larger than a window diameter (0.6 nm) of zirconium-based metal organic skeleton cage holes, phosphotungstic acid is difficult to fall off and easy to recycle. The catalyst has good chemical and thermal stability and can be reused. The catalyst has large specific surface area, can well pre-adsorb reaction substrates and is beneficial for mass transfer effect of the reaction substrates and products. With the highly dispersed catalytic activity center phosphotungstic acid, under a condition without a phase transfer agent, dibenzothiophene in model oil is fully converted into dibenzothiophene sulfone, and dibenzothiophene in the model oil is completely removed. The catalyst is applied in gasoline with about 500 mass ppm, and has the removal rate on organic sulfur reaching 79%. The used raw materials are cheap, the synthesis process flow is simple, the operability is strong, and the catalyst has wide application prospects.

The invention discloses a nickel-molybdenum carbide nanoparticle / carbon fiber composite nano material, a preparation method and application of the nickel-molybdenum carbide nanoparticle / carbon fiber composite nano material in electrocatalytic hydrogen evolution or oxygen evolution, and belongs to the technical field of controllable preparation of non-precious metal-based carbon fiber composite nano materials. The nickel-molybdenum carbide nanoparticle / carbon fiber composite nano material is prepared by utilizing three steps of electrospinning, low-temperature calcining in an air atmosphere andhigh-temperature calcining in an argon atmosphere. The nickel-molybdenum carbide nanoparticle / carbon fiber composite nano material disclosed by the invention exists in fiber morphology, and nickel nanoparticles and molybdenum carbide nanoparticles are uniformly distributed inside or outside carbon fiber. The preparation method disclosed by the invention is low in cost, is simple and easy and canrealize large-scale industrial application. The nickel-molybdenum carbide nanoparticle / carbon fiber composite nano material prepared by the invention is used as an electrocatalysis and water decomposition dual-functional electrocatalyst, excellent catalytic activity is shown, high-efficiency preparation of a pollution-free hydrogen energy source is realized, a new strategy is provided for responding increasingly serious environment problems, and important practical application value is obtained.

The invention discloses a method for preparing m-xylylenediamine. The method includes the following steps that: a fixed-bed hydrogenation reactor is adopted, and isophthalonitrile is dissolved in organic acid amide solvent, and then enters a bed containing catalyst in the form of solution to react with hydrogen under the conditions of the reaction temperature of 50 DEG C to 100 DEG C, preferably 70 DEG C to 90 DEG C, and the reaction pressure of 5MPa to 10 MPa, preferably 7MPa to 8MPa, so that the m-xylylenediamine is prepared. Xylyl diisocyanate (XDI) can be directly prepared by the liquid phase salifying phosgenation method without refining and separating the prepared m-xylylenediamine reaction liquid; the method improves the prior XDA production technique, energy is saved, emission is reduced, the reaction conditions are mild, selectivity is high, the prepared m-xylylenediamine can be directly used for phosgenation reaction without being refined and purified.

The invention discloses an Au-Pd bimetallic catalyst for preparing methyl formate by selective oxidation of methanol. The Au-Pd bimetallic catalyst comprises a carrier and active components, namely Au oxide and Pd oxide, wherein the loading amount of Au is 0.25-5.0wt%, the loading amount of Pd is 0.25-5.0wt%, and the balance is the graphene carrier. The Au-Pd bimetallic catalyst disclosed by the invention has the advantages of low reaction temperature, high catalytic activity and good stability.

The invention discloses a preparation method for an electrocatalytic carbon dioxide reduction electrode, and an application thereof, and belongs to the technical field of electrocatalysis. According to the preparation method for the electrocatalytic carbon dioxide reduction electrode, and the application thereof, Zn-TCPP(Co)-MOF is prepared in a two-step method, a complex formed by metallic cobaltand tetrakis(4-carboxylphenyl) porphyrin is an organic ligand of MOF, and zinc nitrate is a node. Zn-TCPP(Co)-MOF is loaded onto carbon paper to form a Zn-TCPP(Co)-MOF / CP electrode, and excellent catalytic activity and selectivity for a principal product carbon monoxide are shown in an electrocatalytic carbon dioxide reduction system taking 0.5 M CsHCO3 aqueous solution as an electrolyte.

The invention discloses an amorphous nickel-iron oxide nanometer sheet-shaped electrocatalysis material and preparation and application thereof, and belongs to the technical field of electrochemistryenergy converting materials. The amorphous nickel-iron oxide nanometer sheet-shaped thin film material is synthesized in situ on a commercial foamed nickle matrix through a hydrothermal method, and the amorphous nickel-iron oxide nanometer sheet-shaped electrocatalysis material has the advantages of a high specific surface area and many catalytic active sites. The material is applied to a 1M potassium hydroxide solution for electrolysis of water, when the current density is 10 mA.cm<-2>, the overpotential required for oxygen evolution is 206-220 mV, and the performance of the material is better than that of most currently-reported anodic oxygen evolution catalysis materials. Besides, the related preparing technology is simple, raw materials are rich and cheap, the material can replace a precious-metal-based catalyst which is expensive and scarce, and large-scale industrial application of electrolyzed water is promoted.

The invention relates to a bimetallic-activity monatomic catalyst for a metal-air battery and a preparation method thereof and the metal-air battery, and belongs to the technical field of metal-air batteries. The preparation method of the bimetallic-activity monatomic catalyst for the metal-air battery comprises the following steps: 1) adding a cobalt-nickel bimetallic organic framework compound and dopamine hydrochloride or dopamine into an alkaline solution, stirring for 5-8 hours, and carrying out solid-liquid separation to obtain an MOF / PDA nano cubic block, wherein the alkaline solution is a tris buffer solution; and 2) carrying out annealing processing on the MOF / PDA nano cubic block prepared in the step 1) in an ammonia atmosphere to obtain the required product. The metal-air battery prepared from the catalyst prepared by the preparation method of the bimetallic-activity monatomic catalyst for the metal-air battery has better charge-discharge efficiency and longer cycle life than similar batteries.

The invention provides a carbonyl reductase mutant, a recombinant expression vector, a genetically engineered bacterium, a method for preparing the mutant, and the application of the mutant in preparing an optically pure chiral alcohol by asymmetric reduction of a series of prochiral ketones. A catalyst is easy to prepare, reaction conditions are mild, substrate adaptability is wide, environmentalfriendliness is high, recombinant cells can efficiently catalyze the asymmetric reduction of the high-concentration prochiral ketones in a reaction system containing dimethyl sulfoxide and xylose without addition of any coenzymes, and the produced chiral alcohol with high optical purity (ee larger than or equal to 99%) has good industrial application prospects.

The invention discloses a layered two-dimensional material interlayer-confined metal or metal compound composite material as well as a preparation method and application thereof. The composite material comprises a layered two-dimensional material and a metal or metal compound confined among layers of the layered two-dimensional material. The method comprises the following steps: 1) performing lithiation treatment on the layered two-dimensional material to obtain a lithiated layered two-dimensional material; and 2) mixing the dried lithiated layered two-dimensional material, a metal salt and asolvent, performing sealing in a reaction kettle, and performing a hydrothermal reaction to obtain the layered two-dimensional material interlayer-confined metal or metal compound composite material.The preparation method disclosed by the invention can realize controllable preparation of a series of two-dimensional material interlayer-confined metal and metal compound composite materials; and theprepared composite material, especially a two-dimensional molybdenum disulfide interlayer-confined metal hydroxide composite material has the advantages of high electrocatalytic activity and good stability when being used as a hydrogen evolution catalyst, and has application prospects in the field of production of hydrogen by electrolysis of water.

The invention relates to material preparation methods, in particular to a catalyst for a nonterminal olefin hydroformylation reaction and a preparation method of the catalyst. The catalyst is prepared from rhodium complexes and pincerlike diphosphonic amide phosphine ligands and used for the nonterminal olefin hydroformylation reaction. According to the catalyst for the nonterminal olefin hydroformylation reaction and the preparation method and application of the catalyst, the pincerlike diphosphonic ligands containing three coordination sites are provided, the framework of the pincerlike diphosphonic ligands is smaller than that of synthesis of traditional diphosphonic ligands containing xenyl, and compared with an existing catalyst system, when the catalyst decorated with the ligands is used for the hydroformylation reaction containing nonterminal olefin structures, high activity and selectivity are achieved when the catalyst system is used for catalyzing special annular olefin.

The invention provides a V-W-Ti oxide catalyst, a preparation method and an application thereof. The V-W-Ti oxide catalyst comprises, by mass, 5-25% of V2O5, 5-30% of WO3 and 50-80% of TiO2. The V2O5, the WO3 and the TiO2 are uniformly mixed, grain size of each oxide crystal being 1-30 nm independently. The V-W-Ti oxide catalyst is used for selectively catalytic reducing NOx with good catalytic performance and has excellent catalytic performance even under a high space velocity. The catalyst has a wide operation temperature window and has excellent low-temperature activity, nitrogen generation selectivity, water resistance, sulfur resistance and thermal stability within the temperature range of 150-500 DEG C. The preparation method is simple.

A method for photo-catalytic degrading carbamate agricultural pesticide in water is carried out by fixing carrying TiO2 on ceramic slice with porous structure, putting the slice as catalyst slice into photo-catalytic reactor, degrading carbamate agricultural pesticide in water under ultraviolet irradiation, ultrasonic dispersing the superfine TiO2 powder in distilled water to form TiO2 suspensoid, immersing acidified and silanized porous ceramic slice in suspensoid for 2 hrs, baking at 110deg.C in oven for 1 hr, roasting at 600-7002deg.C for 6-8 hrs, and cooling to temperature in drier. Its advantages include low cost, fast speed and no pollution.

The invention belongs to the technical field of catalysts and in particular relates to a biological enzyme-chemical compound catalyst, a preparation method of the catalyst, and an application of the catalyst in preparation of sorbitol. According to the catalyst, a spherical chemical catalyst is bonded to a dendritic biological enzyme catalyst and is of a core-shell structure, the shell structure refers to silica, and the core refers to mesoporous carbon spheres coated with ruthenium nanoparticles. A secondary cross-linked immobilization technology is adopted, the chemical catalyst is bonded by biological enzyme molecules by virtue of a cross-linking agent, the biological enzymes are mutually cross-linked to form a composite catalyst, the sorbitol is produced in an amylolysis-hydrogenation one-pot process and has excellent catalytic activity, the macromolecular biological enzyme is immobilized and can be recycled, the service life is long, the production cost is reduced, and the catalyst has good industrial application prospects. The catalyst disclosed by the invention is mild in reaction, readily available in raw materials, low in price and environment-friendly.

The invention discloses an ultralow-content noble metal composite catalyst for acetylene hydrochlorination reaction and a preparation method thereof, wherein the catalyst is obtained by loading a noble metal-amino acid complex and a co-catalytic component on acid-treated activated carbon, wherein amino acids are cysteine, glutamine, asparaginate and the like, the co-catalytic component is copper chloride, cobalt chloride, cerium chloride, bismuth chloride, cesium chloride and the like; and the catalyst comprises, by mass, 0.05-0.25% of a noble metal component and 0.06-0.90% of the co-catalyticcomponent. According to the preparation method, the noble metal-amino acid complex and the co-catalytic component are sequentially impregnated on the acid-treated activated carbon, the catalyst is obtained by freeze-drying, the preparation process is simple and pollution-free, the method is suitable for industrial scale production, the catalyst has excellent catalytic activity, selectivity and long service life in the acetylene hydrochlorination reaction, the acetylene conversion rate can be kept above 98.5% in a long-time operation; the chloroethylene selectivity is more than 99%.

The invention relates to a modification method for titanium silicalite molecular sieves, which aims to further improve the catalytic activity and stability of the titanium silicalite molecular sieves. The method is used for processing a titanium silicalite molecular sieve subjected to strip extrusion molding, so that a carrier introduced by strip extrusion can be crystallized and formed into a new molecular sieve skeleton with catalytic activity, and no negative impact is produced on the strength of the strip titanium silicalite molecular sieve. Compared with modified molecular sieves prepared in the prior art, the modified titanium silicalite molecular sieve prepared by using the modification method has higher catalytic activity and a longer service life to selective catalytic oxidation reaction such as alkene epoxidation, phenol hydroxylation, and ketone ammoxidation.

The invention provides an efficient CH4-SCR denitration catalyst under an oxygen-enriched condition and a preparation method and application thereof. The efficient CH4-SCR denitration catalyst is characterized in that the active component of the efficient CH4-SCR denitration catalyst is indium, the indium is supported on an H-Beta molecular sieve, and the weight content of the indium is 5.52-8.20wt% of that of the H-Beta molecular sieve. Compared with the prior art, the efficient CH4-SCR denitration catalyst has the advantages that the catalyst has good selective catalytic activity under high O2 concentration and high air speed, NOx removing rate is close to 100%, CH4 utilization rate can exceed 100%, and the catalyst is wide in activity temperature window and good in SO2 resistance.

The invention provides a preparation method of a carbon nitride quantum dots-modified inverted opal g-C3N4 catalyst. The carbon nitride quantum dots-modified inverted opal g-C3N4 catalyst can be wellused to degrade organic wastewaters, such as phenols, under the action of visible light. Three-dimensionally and orderly arranged silica (SiO2) is used as a hard template and dihydrogen diamine (DCDA)as a precursor to synthesize inverted opal g-C3N4 (CN IO) photonic crystal structure. The CN IO is subjected to loading modification of carbon nitride quantum dots (CNQDs), and optimal loading capacity is investigated. The preparation method enables the large pore diameter of inverted opal structure to be controlled by changing the particle size of the hard template; loading capacity of CNQDs iscontrolled by changing the addition of the CNQDs solution. By applying the catalyst herein to degrade phenolic wastewaters, it is discovered that the catalyst can quickly degrade organic pollutants under the action of visible light; the catalyst herein has better catalytic activity than common carbon nitride (bulk-CN) and CN IO materials.

The invention discloses a graphene loaded cerium catalyst and a preparation method thereof, relating to the technical field of catalysts. The preparation method of the graphene loaded cerium catalyst comprises the following steps: mixing the prepared cerium oxide suspension and graphene oxide suspension, heating to 160-180 DEG C, and performing hydrothermal reaction for 6-10h; removing the supernatant to obtain solid sediment; and drying. The product obtained by the preparation method has perfect catalytic activity against heterocyclic organic compounds; and the method is easy to operate and suitable for industrial application. The graphene loaded cerium catalyst is prepared by the method and comprises active catalytic components, namely cerium dioxide and a graphene carrier and has fairly high catalytic activity in catalyzing heterocyclic organic compounds.

The invention discloses a method for preparing cyclohexanol and cyclohexanone. The method comprises the steps of taking cyclohexane as raw material, taking hydrogen peroxide aqueous solution as oxidant and performing catalytic oxidation under the action of a catalyst so as to prepare the cyclohexanol and the cyclohexanone, wherein the catalyst is (An)[M4(H2O)y(ZW9Ox)2]. The method has the advantages of high conversion rate of the cyclohexane, high selectivity of the cyclohexanol and the cyclohexanone and easy regeneration of the catalyst.

A strong-acidity solid SBA-15-Ph-SO3H catalyst for preparing synthetic fiber Nylon-6, cosmetics and food by Beckmann reforming reaction and esterifying reaction is prepared from ethyl n-silicate (TEDS) as Si source, triblock copolymer Pluronic 123 (P123) as template agent and 2-(4-phenylsulfuryl chloride) ethyl trimethyl silicate (CSPTMS) as phenylsulfonyl precursor. It has high catalytic activity to said two reactions.

The invention provides a method for preparing dicarboxylic acid zinc. The method comprises the following steps: reacting a dicarboxylic acid sodium aqueous solution and a zinc chloride aqueous solution, so as to obtain dicarboxylic acid zinc. Compared with the prior art, the method takes water as a reaction solvent and avoids adopting organic solvents such as methylbenzene and acetone as the reaction solvent, and a by-product only comprises sodium chloride, so that the environmental pollution is reduced. The dicarboxylic acid zinc prepared by the method can be used for polymerization reaction of carbon dioxide and epoxide and has good catalytic activity. The method is simple, saves energy, and conforms to the concept of environmental protection. Experimental results show that the dicarboxylic acid zinc prepared by the method catalyzes the polymerization reaction of carbon dioxide and epoxy propane to generate polycarbonate, and the yield is 18.4-38.2g polymer / g catalyst.

The invention discloses a high-efficiency catalyst for degrading water body COD (Chemical Oxygen Demand) by ozone and a preparation method thereof. The catalyst is prepared from active alumina ball carriers and iron and cerium compound oxide active ingredients, wherein the active alumina ball is taken as the carrier, the carrier is prepared through roasting pretreatment, ferric salt and cerium salt dipping, alkali treatment, centrifugal washing, drying and calcination. Under a condition that ozone concentration is 20mg / L and flow rate is 0.2L / min, the wastewater of which the initial COD concentration is 500mg / L is processed for 30min, and a COD removal rate is 90% or more so as to achieve the national first-degree discharge standard. In a catalyst use process, a metal loss amount is small,performance is excellent, and in addition, the high-efficiency catalyst has the advantages of simple preparation technology and no waste gas and is favorable for industrial production.

The invention discloses an environment friendly polyester polycondensation catalyst and a method for preparing polyester by using the catalyst. The catalyst has a following structure, wherein, M represents doped metal ions, and X represents anions. The catalyst is prepared by the following steps: dissolving aluminium compound in glycol, adding an aqueous solution doped with metal salt at the temperature of 80-95 DEG C, stirring for 0.5-2 h at the temperature of 80-95 DEG C, then heating to 95-120 DEG C and stirring for 0.5-1 h, and finally adding stabilizing agent, phosphorous compound, and mixing uniformly. The stabilizing agent, phosphorous compound, and the aluminium compound can be separately added in the reaction system. The activity of the liquid aluminium catalyst is equal to that of the antimony catalyst, and the polyester hue of the liquid aluminium catalyst is equal to that of the antimony catalyst.