418results about How to "High low temperature activity" patented technology

The invention provides an SCR (selective catalytic reduction) catalyst for denitrating low-temperature smoke of a cement kiln and a preparation method thereof. The SCR catalyst is characterized in that by adjusting the technological conditions such as proportions of active components, mass ratio of carriers and active components, calcining temperature and the like, a composite metal oxide which is formed by one or more metal elements out of manganese (Mn), ferrum (Fe), copper (Cu), cerium (Ce), lanthanum (La), bismuth (Bi), niobium (Nb), tantalum (Ta) and the like is loaded on a carrier by adopting an impregnation method, and tungsten and molybdate are used as active assistants. The active components in the SCR catalyst are uniformly distributed on the surface of the carrier in an unformed shape, the low-temperature activity of the catalyst is improved by utilizing the synergistic effect of multiple metals, the SCR catalyst is particularly suitable for the denitration of the smoke which is discharged from a dust collector on the tail of the cement kiln, the denitration rate can reach higher than 70 percent at the temperature of 80 DEG C, the denitration rate is higher than 90 percent in the temperature range of 125 DEG C to 200 DEG C, and the toxicity resistance is strong.

The invention relates to a titanium oxide supported ferric vanadate catalyst. The catalyst is composed of a TiO2 carrier, and a FeVO4 active constituent supported on the TiO2 carrier. In term of the mass of the catalyst as 100wt%, FeVO4 is 1.5-15 wt%, preferably 2.5-13.5 wt%, further preferably 8-10 wt%, and most preferably 9 wt%. According to the invention, the TiO2 supported FeVO4 catalyst is used for purifying fixed-source and movable-source nitric oxides in NH3-SCR (selective catalytic reduction) reaction for the first time; and moreover, the preparation method for the catalyst is simple and practicable, and easily realizes industrialized production. The FeVO4/TiO2 catalyst disclosed by the invention is extremely excellent in anti-H2O-poisoning and anti-SO2-poisoning performances in the NH3-SCR reaction, and very suitable for practical application.

The invention relates to a mercury-free catalyst used for acetylene hydrochlorination for synthesizing vinyl chloride, and a preparation method and an application thereof. The preparation method comprises the following steps: 1, dissolving alkali metal salt and an amide solvent in water to prepare a mixed solution; 2, adding active carbon into the mixed solution obtained in step 1, and dipping the active carbon; and 3, filtering the active carbon obtained in step 2, draining the filtered active carbon, and heating and drying the drained active carbon to obtain the catalyst. The concentration of raw gas on the surface of the catalyst is increased through using the synergism of the alkali metal salt and the amide solvent and the adsorbing and dissolving ability of the amide solvent to raw materials comprising acetylene and hydrogen chloride, and the amide solvent is a high-polarity aprotic polar solvent, and has a polarization effect on reactants, so the reaction efficiency is further improved, the low temperature activity of the catalyst is high, and the selectivity and the stability are good.

The present invention relates to a method of removing nitrogen oxides from the exhaust gas of a lean-burn internal combustion engine by selective catalytic reduction (SCR) using ammonia. The exhaust gas is routed first over a platinum-containing pre-catalyst and then over an SCR catalyst. The ammonia needed for the selective catalytic reduction is added to the exhaust gas upstream of the pre-catalyst at an exhaust-gas temperature below 250° C., while it is supplied to the exhaust gas between the pre-catalyst and the SCR catalyst at an exhaust gas temperature above 150° C. By adopting this procedure, a very large temperature range for the selective catalytic reduction with high nitrogen conversion rates is obtained.

The invention belongs to the technical field of environmental protection and catalysts, and particularly relates to a catalyst for selective catalytic reduction of nitric oxide and a preparation method of the catalyst. The catalyst comprises a molecular sieve and transition metal supported on the molecular sieve and is prepared from the molecular sieve and a transition metal precursor, and the molecular sieve is dried to remove adsorbed water; then the metal precursor is mixed with water, stirring is carried out for dissolving, and a solution is prepared; the prepared solution and the prepared molecular sieve are stirred and mixed, standing, drying and calcining are carried out, the product is cooled to normal temperature, and the catalyst for selective catalytic reduction of nitric oxide is obtained. The molecular sieve is used as a carrier, an effective surface is provided for adsorption and reacting of nitric oxide, high dispersion of active components can be kept, and the use amount of the active components can be reduced. By means of the characteristics of the carrier and the synergetic effect among different kinds of metals, the low temperature activity of the catalyst is improved, and the active window temperature range of the catalyst is widened. The preparation method of the catalyst is simple, easy to carry out and free of pollution.

The invention relates to a non-noble metal mercury-free catalyst for acetylene hydrochlorination reaction, a preparation method and application thereof. The preparation method comprises the steps of: 1) preparing a mixed solution of a copper salt, an ammonium salt and phosphoric acid, or a mixed solution of a copper salt, an ammonium salt and phosphate; 2) adding activated carbon into the mixed solution obtained in step 1 for soaking; 3) spin-drying the soaked activated carbon, and conducting heating and drying to obtain the catalyst. Through the synergistic effect of multiple components, the catalyst prepared by the method provided by the invention acquires good catalytic stability and high low-temperature activity, and under a reaction temperature of 130DEG C and the existing mercury catalyst running pressure condition and feeding intensity, more than 96% of conversion per pass and more than 99% of vinyl chloride selectivity can be obtained. As the technical conditions of the catalyst for acetylene hydrochlorination reaction are similar to those of the existing mercury catalyst, renovation of existing equipment is unnecessary, and the mercury catalyst can be replaced easily on the existing equipment.

An arrangement and method for reducing the nitrogen oxide content in the exhaust gas of an internal combustion engine with the aid of ammonia and/or ammonia-releasing reduction agents, whereby ammonia and/or ammonia-containing reduction agent is added to the exhaust gas stream upstream of a catalyst combination composed of an SCR catalyst and a subsequent NH₃-oxidation catalyst in such a way that a homogeneous mixture of exhaust gas and ammonia is present upstream of the SCR catalyst. To optimize the reaction or conversion of nitrogen oxides, disposed downstream of the combination of a first SCR catalyst and a first NH₃-oxidation catalyst is at least one second catalyst having SCR activity in order in this way to reduce the nitrogen oxides formed at the first NH₃-oxidation catalyst due to insufficient selectivity of the catalyst to nitrogen with not yet oxidized NH₃.

The invention involves a new preparation method for amorphous alloy catalyst, it uses KBH4 as reductant, mixes one or two of nickel sulfate, nickel acetate, nickel nitrate, nickel chloride, cobalt sulfate or cobalt chloride into main salt and dissolves them into solution of ethylenediamine, tartaric acid or tartrate, prepares non-load or load amorphous alloy catalyst using oxidant, molecular sieve and high polymer as the carrier. The amorphous alloy catalyst prepared through the invention has characteristics of small dimension of active components, good dispersion degree, high yield of catalyst and high catalyst activity, and it applies to catalyzing hydrogenation and hydrogenation dechlorination reaction.

The reformate olefine saturation hydrogenation method includes the following steps: in the presence of one kind of catalyst making the reformate contact with hydrogen gas, its contact temp. is 200-320 deg.C, contact pressure is not less than 0.7 MPa, liquid hourly space velocity is 1-8 hr (-1), and volume ratio of hydrogen and oil is not less than 30. The described catalyst contains tungsten oxide and/or molybdenum oxide, nickel oxide and cobaltous oxide loaded on the alumina, the catalyst is used as reference, the content of the described tungsten oxide and/or molybdenum oxide is 4 wt% to less than 10 wt%, the content is nickel oxide is 1-5 wt%, the content of cobaltous oxide is 0.01-1 wt% and the ratio of total atomicity of nickel and cobalt and total atomicity of nickel, cobalt, tungsten and/or molybdenum is 0.3-0.9.

The invention provides a coke-oven gas methanation catalyst and a preparation method thereof. The coke-oven gas methanation catalyst is prepared by loading a certain amount of active ingredients Ni on composite oxide TiO2-ZrO2-SiO2 serving as a carrier, and using rare-earth elements RE and metal M as aids. The catalyst has the advantages which cannot be achieved by other methanation catalysts. The catalyst has the characteristics of high low-temperature activity, sulfur resistance capacity, good high temperature resistance performance and the like, and the function of hydrocarbon cracking andgood antioxidation performance and the like and is easy to prepare.

The invention discloses a multi-complex-metal-oxides catalyst and the preparation method. The catalyst carrier is multi-complex-metal-oxides solid alkali or surface solid alkali or the precursors of the solid alkali or surface solid alkali. The multi-complex-metal-oxides is complex oxides by combining two or more than two selections from alumina, titania, zirconium dioxide and ceria with one or more than one selections from magnesia, calcium oxide, baryta, potassium oxide and sodium oxide. Active ingredient is composed of cobalt oxides or /and nickel oxide and molybdenum trioxide or/and tungsten trioxide. The additive added to carriers or active components is the oxide of at least one of the following elements: cerium, lanthanum, zinc, zirconium, nickel or manganese. The invention has the advantages of high activity, high activity at low-temperature, high activity stability and wide temperature range of activity; high intensity, high intensity stability and high anti-hydration and anti-pulverization ability, wide water/gas ratio adaptability and wide range for impurity content. The catalyst of the invention is applied to the promotion of dirty water gas shift reaction.

The invention provides a NH3 selective oxidation catalyst; the NH3 is selectively catalytically oxidated as N2 and H2O without pollution. The catalyst mainly solves the problems that the oxidation catalyst which is applied to elimination industries and traffic and the like and generates the NH3 pollution has bad low-temperature activity, low selectivity and poor anti-sulfur performance. The catalyst firstly prepares Fe-ZSM-5 molecular sieve catalyst with large specific area by a secondary ion exchanging method; subsequently, trace noble metal Pt is loaded on the Fe-ZSM-5 so as to prepare the Ptx-Fe-ZSM-5 catalyst; and the oxidation catalyst has high activity, N2 selectivity, good stability and anti-SO2 poisoning performance, and excellently solving the technical problem of the prior art. If the catalyst is prepared into slurry and loaded on honeycomb ceramics, the NH3 pollution in the practical industrial tailings can be expected to be removed; furthermore, the catalyst can be used as postpositive oxidation catalyst in the tailings disposal system of diesel engine so as to prevent the pollution caused by the leakage of NH3 in the NH3-SCR catalytic system.

The invention discloses a low-temperature low-SO2-oxidation-rate honeycomb denitration catalyst and a preparation method thereof. The catalyst is prepared from, by mass, 1-5% of V2O5, 0.01-6% of WO3, 0.01-10% of MoO3, 0.01-0.5% of MgO, 3-6% of glass fibers, 66.5-95.96% of TiO2 and one or more of 0.01-1% of B2O3, 0.01-1% of F, 0.01-2% of P2O5, 0.01-1% of SnO2 and 0.01-1% of Sb2O3. Anatase type titanium dioxide serves as a carrier, V2O5 serves as an active center, and auxiliary agents including MgO, B2O3, F, SnO2, P2O5, Sb2O3 and the like are added to enhance synergistic effects among the active center, the auxiliary agents and the carrier to realize preparation of the low-temperature low-SO2-oxidation-rate honeycomb denitration catalyst. Compared with existing industrial V2O5-WO3-TiO2 catalysts, the denitration catalyst prepared according to the method has advantages of wide operating temperature window, high denitration efficiency, low SO2 oxidation rate, high water resistance, less proneness to hole blockage, long service life and the like and is especially suitable for low-temperature conditions (200-300 DEG C).

The invention relates to a production method of methyl glycolate, aiming to mainly solve the problems of low conversion rate of dimethyl oxalate and low selectivity of methyl glycolate in the prior art. The production method of methyl glycolate comprises the following steps of (1) enabling a mixed material composed of a methanol solution of dimethyl oxalate and feed gas containing hydrogen to be in contact with a silver-containing catalyst in a reactor to react to obtain a mixture flow containing methyl glycolate, carrying out heat exchange, and then, enabling the mixture flow to enter a gas-liquid separation system; (2) sequentially carrying out condensation, primary gas-liquid separation, condensation and secondary low-temperature gas-liquid separation on the mixture flow subjected to heat exchange to obtain crude methyl glycolate; and (3) carrying out reduced-pressure distillation separation on crude methyl glycolate to obtain the methyl glycolate product. According to the technical scheme, the conversion rate of dimethyl oxalate can be higher than 99%, the selectivity of methyl glycolate can be higher than 80%, and the production method can be applied to industrial production of methyl glycolate.

The invention relates to a cerium-molybdenum-zirconium (Ce-Mo-Zr) composite oxide catalyst. The molar ratio of Zr to Ce in the catalyst is 1:2, and the molar ratio value of Mo to Ce is 0.1-1.5. By the adjustment of the ratio of the three elements, namely cerium, molybdenum and zirconium, the catalyst which is wide in temperature window, high in conversion rate and excellent in temperature resistance and sintering resistance, and is used for converting nitrogen oxides is obtained; the preparation process is simple, the cost is low, and the realization of the industrialization is facilitated.

A microwave aided process for preparing the catalyst of non-crystalline NiB alloy suitable for catalytic hydro-reaction with high catalytic active features that the chemical reduction and chemical plating in microwave field is used, KBH4 is used as reducer, its primary salt is chosen from nickel sulfate, nickel acetate, etc, its secondary salt is chosen from cobalt chloride, iron chloride, etc, its carrier is chosen from oxide, molecular sieve, etc, its solvent is chosen from water, tetrahydrofuran, etc and the complex agent, stabilizer and additive is used.

The invention discloses a methanation catalyst of carbon oxides containing nickel, the methanation catalyst contains active components of a) nickel oxide, b) tungsten oxide and/or molybdenum oxide, and c) at least one active component which is selected from alkali metal oxides, alkaline earth metal oxides and rare earth metal oxides which are loaded on a carrier of the oxides, and the carrier of the oxides is aluminium oxide, silicon oxide, titanium oxide, zirconium oxide or the mixture thereof. The catalyst of the invention has very high activity at low temperature, high anti-poisoning capacity and thermal stability and broad application prospect.

Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25: 1 to about 1:1.

The invention provides a preparation method of a catalytic material mixed by copper and cerium oxide. The preparation method comprises the following steps of: (a) dissolving copper salt in a solvent, and continuously mixing the copper salt for 0.5-1 hour, wherein the concentration of Cu ions is 0.00872-0.17492 mol/mL; (b) adding mesoporous cerium oxide powder into a copper salt solution obtained by the step (a) according to the liquid-to-solid ratio of 10:1 to 6:1, stilling the copper salt solution for 24-48 hours after the mesoporous cerium oxide powder is dissolved, and meanwhile, aperiodically stirring the copper salt solution; (c) drying the mixed solution obtained by the step (b) at 110-120 DEG C for 10-12 hours, grinding the dried resultant, and calcining the resultant at 200-300 DEG C for 2-3 hours, thus obtaining the catalytic material mixed by the copper and the cerium oxide. The preparation method has the advantages of simplicity in operation and experimental procedure, low cost of raw materials, and no environmental pollution, and the prepared catalytic material has the advantages of large specific surface area and pore volume, high low-temperature activity and favorable thermal stability. The prepared catalytic material can be widely applied to optical CO oxidation sensors, motor vehicle exhaust gas cleaning and purification systems and the like, and is prone to industrial production.

The invention discloses a low-temperature high-activity methanation catalyst and a preparation method thereof. The catalyst comprises metallic nickel as an active component, AL2O3 as a carrier and MgO as a structure auxiliary agent, and an appropriate amount of lanthanum oxide and manganese oxide are added as active auxiliary agents. The catalyst comprises the following main components in percentage by mass: 18-45% of NiO, 40-70% of Al2O3, 5-30% of MgO, 0.4-5% of La2O3 and 0.1-5% of MnO2. The catalyst disclosed by the invention has the advantages of large specific area, uniform nickel dispersity, good heat stability, strong oxidation resistance, low active temperature, adaptability to low hydrogen-carbon ratio and the like. The catalyst is applicable to preparation of LNG (liquefied natural gas) through methanation of industrial gases including coke oven gas, coal synthesis gas, semi coke exhaust gas and the like rich in CO, CO2 and H2, is particularly applicable to a methanation reaction in a low-temperature section, and can effectively improve the quality of synthetic natural gas. Meanwhile, the invention also provides the preparation method of the catalyst, and the preparation method is simple in process flow and can realize industrial production easily.

There are provided a catalytic diesel particulate filter that is arranged in an exhaust system of a diesel engine and includes a catalyst that burns a particulate matter contained in an exhaust gas from the diesel engine, wherein the catalyst is configured in such a manner that a ceria based catalyst coat layer 6 containing no noble metal and a noble metal based catalyst coat layer 11 containing a noble metal are separately provided on a substrate constituted of a honeycomb structure, and a method for producing the same.