58results about How to "Wide operating temperature window" patented technology

The invention relates to a cerium-zirconium-tungsten composite oxide catalyst used for carrying out selective catalytic reduction on nitric oxide by ammonia, as well as a preparation method and usage thereof. The catalyst is a composite metal oxide formed by three types of metal including cerium, zirconium and tungsten. The catalyst adopts non-toxic and harmless raw materials; the cerium-zirconium-tungsten composite oxide catalyst which can adapt to high space velocity reaction condition and has the characteristics of being excellent in catalytic activity, high in N2 generation selectivity, wide in operating temperature window and the like can be prepared by using a simple and practicable method; and the cerium-zirconium-tungsten composite oxide catalyst is suitable for a nitric oxide catalytic purification device used for a moving source represented by diesel exhaust and a fixed source represented by flue gas of a coal-fired power plant.

The invention discloses a CeO2-ZrO2 based SCR (selective catalytic reduction) catalyst used for denitration and a preparation thereof and belongs to the field of nitric oxide post-processing purification. The catalyst has a three-layer structure, wherein cordierite honeycomb ceramic is used as a carrier; an active coating is loaded on the carrier; a modifying coating is loaded on the active coating; the cordierite carrier has a skeleton carrying function; the active coating of the catalyst mainly has a function of activating NOx and NH3; and the modifying coating mainly has functions of storing NH3, avoiding deep oxidation of NH3 on the surface of the catalyst when the catalyst is used at a high temperature and increasing the sulfur poisoning resistance of the catalyst. The preparation process of the catalyst is simple and can be easily industrialized. A working temperature window of the optimized catalyst can reach 250-450 DEG C, and denitration efficiency is above 80%. The catalyst has the significant advantage of being nontoxic and has excellent heat stability and excellent SO2 poisoning resisting property.

The invention relates to an SCR (selective catalytic reduction) nitrogen oxide catalyst, and a preparation method and application thereof, belonging to the field of catalysis. The SCR nitrogen oxide catalyst is a composite oxide catalyst composed of manganese and at least one transition metal. The SCR nitrogen oxide catalyst is prepared from non-poisonous raw materials through a method which is simple and easy to operate, and has the advantages of wide operating temperature window, good low-temperature activity and excellent N2 generation selectivity. Thus, the catalyst is very suitable for the purification of nitrogen oxide in flue gas from coal-fired power plants representative of stationary sources.

The invention relates to a transition metal doped cerium and titanium compound oxide catalyst for selective catalytic reduction of nitric oxide by ammonia, and a preparation method thereof. The catalyst in the invention is a transition metal (iron, tungsten and molybdenum) doped cerium and titanium compound oxide catalyst. The preparation method of the catalyst is a co-precipitation method, which comprises the following steps of: preparing mixed solution from cerium salt, titanium salt and salt corresponding to one or more transition metals of iron, tungsten and molybdenum, and continuously stirring for 3 to 15 hours at the temperature of between 50 and 150 DEG C by using one of ammonia water, sodium hydroxide, sodium carbonate, ammonium bicarbonate or urea; and filtering, washing, baking and calcining. In the invention, the adopted raw materials are non-toxic and harmless, the preparation method is simple and easy, the prepared catalyst has the characteristics of high catalytic activity, excellent N2 generation selectivity, broad operation temperature window, high space velocity reaction condition adaptability and the like, and is suitable for mobile sources represented by tail gas of diesel vehicles, as well as stationary source nitric oxide catalytic purification device represented by flue gas of coal fired power plants.

The invention discloses a double-perovskite metal oxide catalyst. The formula of the double-perovskite metal oxide catalyst is LaSrFeMo1-xCoxO6, wherein x is greater than or equal to 0.1 and less than or equal to 1. The invention discloses four methods, that is, a coprecipitation method, a gel-sol method, a reversed-phase microemulsion method and a hard template method in all to prepare a series of double-perovskite metal oxide catalysts. As nitrate, ammonium carbonate, citric acid, glucose and the like are taken as raw materials, the double-perovskite metal oxide catalyst is wide in raw material source, easy to prepare and low in cost; under conditions of specific reaction steps and process parameters, a complete double-perovskite crystal form is formed through specific high-temperature roasting, the whole preparation method is simple, and the yield is relatively high.

The invention discloses a heteropoly-acid-doped cerium oxide SCR denitration catalyst. The heteropoly-acid-doped cerium oxide SCR denitration catalyst is characterized in that heteropoly acid is Keggin-type phosphotungstic acid HPW, and the doped amount of the heteropoly acid is 5wt% to 15wt%. According to the catalyst, anatase TiO2 serves as a carrier, a mixture of cerium oxide CeO2 and the Keggin-type phosphotungstic acid HPW loaded to the carrier serves as an active component, and the catalyst is represented as CeO2-HPW/TiO2. The catalyst contains the following ingredients by content: 65wt% to 85wt% of TiO2 and glass fibers, 5wt% to 20wt% of CeO2 and 5wt% to 15wt% of HPW. The invention further discloses a preparation method for the catalyst and an application of the catalyst. The catalyst has relatively high catalytic oxidation-reduction power and acidic sites and achieves relatively high catalyst reaction activity at relatively low reaction temperatures, so that the low-temperature denitration efficiency and sulfur resistance are effectively improved.

The invention provides a cerium-based catalyst loaded with transition metal as well as a preparation method and a purpose thereof. For the cerium-based catalyst loaded with transition metal, a catalyst carrier is CeO2; active ingredients are transition metal oxides loaded on the carrier; through being metered by that the mass of the CeO2 carrier is 100 percent, the mass of the transition metal oxides is 5 to 20 percent. The cerium-based catalyst loaded with transition metal provided by the invention has the NOx purification efficiency being near 100 percent in the temperature range of 200 to 440 DEG C; the operation temperature window is wide. The preparation method is simple; the prepared cerium-based catalyst loaded with transition metal can be used for NOx catalytic purification in the NH3-SCR process.

The invention relates to a preparation method and applications of a monolithic catalyst used for catalyzing and purifying ammonia-containing waste gas. The monolithic catalyst consists of two parts, namely a honeycomb-shaped metal wiremesh carrier and a catalytic active component, wherein the honeycomb-shaped metal wiremesh carrier material is a FeCrAl stainless steel wiremesh; and the catalytic active component consists of a metal active component and an inorganic oxide carrier; the metal active component is one or more of Ag, Cu, Fe and Mn; and the inorganic oxide carrier is one or more of Al2O3, TiO2, SiO2, ZrO2 and CeO2. The monolithic catalyst has a three-dimensional permeating structure and properties such as higher heat transfer coefficient and mass transfer coefficient and lower pressure drop, is suitable for the installations of various reactors and can be directly applied in the industrial field. For example, the Ag/Al2O3 honeycomb-shaped metal wiremesh catalyst can be used for completely converting NH3 at 220 DEG C and have higher selectivity to N2 (>80%); and the catalyst has high stability and wide operating temperature window and is insensitive to the change of space velocity.

The invention discloses a simultaneous desulfurization and denitration catalyst and preparation method of the simultaneous desulfurization and denitration catalyst. The desulfurization and denitration catalyst is composed of 60-80 parts by weight of carrier activated carbon (AC), 2-40 parts by weight of active ingredient neodymium oxide (Nd 203) and 0-20 parts by weight of promoter cobalt monoxide (CoO), wherein the total parts by weight of the activate ingredient and the prompter is 2-40. Detailed preparation method is explained in an introduction book. The simultaneous desulfurization and denitration catalyst and preparation method of the simultaneous desulfurization and denitration catalyst has the advantages of being wide in catalyst source, easy to obtain, easy in a preparation and regeneration method, high in catalyst mechanical strength, small in erosion, high in using efficiency of raw materials, suitable for mass production, high in catalyst activity, wide in operation temperature range, capable of being tested in a simulation test for a long time within a temperature range from 350 DEG C to 500 DEG C, and capable of acquiring a desulfurization denitration rate over 90 percent.

The invention relates to a tungsten oxide surface modified Fe2O3 catalyst comprising the following chemical compositions: WOx/Fe2O3(x=2-3), wherein the mass percent of WOx in the catalyst is 1-10 wt.%. The invention further discloses a method for preparing the catalyst. The NH3 selective catalytic reduction activity of surface non-modified Fe2O3 material into NOx (NH3-SCR) is extremely low, the operation temperature window is extremely narrow, and a large amount of N2O side product is generated, but the NH3-SCR catalyst activity and the N2 generation selectivity are remarkably improved after WOx surface modification. The tungsten oxide surface modified Fe2O3 catalyst as well the preparation method and the application thereof are suitable for catalytic elimination of stationary source and mobile source NOx.

The invention discloses a cerium based oxide catalyst for ammonia selective catalytic reduction nitric oxide, a preparation method as well as application of the catalyst. The catalyst is prepared by the following steps: carrying out controllable regulation on the pH value in the preparation process; forming a metal oxide catalyst CeO(i)x(/i)/WO(i)y(/i)-TiO2 and cerium oxide CeO(i)x(/i) by fractional precipitation, and uniformly dispersing on the surface of a tungsten titanium composite oxide WO(i)y(/i)-TiO2. The cerium based oxide catalyst which has the characteristics of excellent low-temperature catalytic activity, high N2 generation selectivity, wide operation temperature window, capability of being adaptive to high-airspeed reaction conditions and the like is prepared from nontoxic and harmless raw materials by a simple and feasible method, and is suitable for nitric oxide catalytic purification devices with mobile sources represented by tail gas of a diesel vehicle and fixed sources represented by flue of coal burned power plants.

The invention discloses a preparation method of a catalyst for surface sulfation of ferric oxide. The method comprises the following steps: (1) preparing ferric oxide; (2) performing sulfation treatment on the surface of the ferric oxide to obtain a ferric oxide catalyst of which the surface is sulfated. The ferric oxide catalyst with the enhanced surface acidity and the proper oxidation-reduction capacity is synthesized for the first time through performing sulfating process on the surface of the ferric oxide, so that the NOx purification activity of middle and high temperature sections in NH3 selectively reducing NOx (namely NH3-SCR) reaction is obviously improved, an operation temperature window is obviously broadened, and the catalyst has the extremely excellent SO2 poisoning resistance performance and is very applicable for catalytic elimination of a stationary source and a mobile source NOX.

The invention relates to iron-tungsten-titanium composite oxide catalyst. The catalyst has the chemical composition of FeWaTiOx, wherein a is greater than 0 and less than or equal to 1.6. The invention further discloses a preparation method of the catalyst, which comprises the following steps: (1), preparing the solutions of Fe source, W source and Ti source in the presence of oxalic acid, and mixing the solutions of Fe source, W source and Ti source to obtain a mixed solution; and (2), adding excessive urea precipitation agent into the mixed solution to ensure that ions can be fully deposited, and carrying out suction filtration, washing, drying and baking to obtained sedimentation products to obtain the iron-tungsten-titanium composite oxide catalyst. Compared with iron-tungsten-titanium composite oxide catalyst without adulteration, the iron-tungsten-titanium composite oxide NH3-SCR catalyst has an obviously improved high-temperature thermal stability, and is easier to apply to catalysis and decontamination of NOx in heavy duty diesel exhaust.

The invention relates to a cerium-tin-based composite oxide catalyst for catalytic purification of nitrogen oxide and a preparation method thereof, and application of the cerium-tin-based composite oxide catalyst for catalytic purification of nitrogen oxide. The catalyst has the following chemical composition: cerium tin oxide and oxide of M, wherein M is selected from any one or a combination ofat least two of P, Ti, Zr, V, Mn, Fe, Cu, Al, Si, Ni, Hf, Nb, Ta, Cr, Mo, W or Re. Non-toxic and harmless raw materials are adopted, the cerium-tin-based composite oxide catalyst which has the characteristics of high catalytic activity, high hydrothermal stability, excellent N2 generation selectivity, the wide operation temperature window, adaptability to high space velocity reaction conditions and the like is prepared by adopting a simple and feasible method. The cerium-tin-based composite oxide catalyst is suitable for a moving source represented by diesel vehicle tail gas and a fixed sourcenitrogen oxide catalytic purification device represented by coal-fired power plant flue gas.

The invention discloses a cerium based oxide catalyst for catalytic purification of nitrogen oxides and a preparation method thereof. The catalyst is a layered structure CeOx/MoO3-TiO2 catalyst formed by step-by-step uniform precipitation based on controllable adjustment of a pH value in the preparation process. According to the invention, non-toxic and harmless raw materials are employed to prepare the cerium based oxide catalyst with the characteristics of excellent catalytic activity, high N2 generation selectivity, wide operation temperature window and the like through a simple and practicable method. The catalyst is suitable for nitrogen oxide catalytic purification devices adopting a diesel vehicle exhaust represented mobile source and a coal-fired power plant flue gas represented stationary source.

The invention discloses a cerium titanium supported vanadium catalyst. The catalyst is composed of a CeaTibOx support and a V2O5 active component supported on the support, a ratio of a:b is 0.5:1-2:1, and the weight of the V2O5 active component accounts for 1-10% (except 3%) of the weight of the CeaTibOx support. The NOx purifying efficiency of the catalyst is close to above 100% at 200-400DEG C, and the catalyst has a very good NH3-SCR activity, a greatly widened operation temperature window and an excellent SO2 poisoning resistance, and can be used for catalyzing the NOx purification in an NH3-SCR process.

The invention discloses a manganese-based oxide catalyst for catalytic purification of nitrogen oxide and a preparation method thereof. The preparation method comprises the following steps: preparing a Mn3CeW0.3Ox composite oxide by using a uniform precipitation method and then carrying out roasting so as to obtain the (MnOx)3-CeO2-(WO3)0.3 oxide catalyst. According to the invention, the manganese-based oxide catalyst with the characteristics of a wide temperature window, excellent resistance to water and sulfur, high N2 generation selectivity, high-temperature resistance, heat stability and the like is prepared from nontoxic and harmless raw materials by using the simple and easily practicable method; and the prepared manganese-based oxide catalyst is applicable to a nitrogen oxide catalytic purification apparatus with flue gas of a coal-fired power plant as a representative fixed source and tail gas of a diesel car as a representative movable source.

The invention relates to the technical field of catalysis, in particular to SSZ-13 molecular sieves, production, an SCR catalyst and production. A production method of the SSZ-13 hydrogen-type molecular sieves comprises the steps of (1) mixing an aluminium source, a template composition, a silicon source and an alkaline aqueous solution, and carrying out a gelation reaction to obtain gel; and (2)conducting crystallization, calcination and ammonium exchange on the gel to obtain the SSZ-13 hydrogen-type molecular sieves. The template composition comprises N,N,N-trimethylbicyclo[2,2,2]octane-2-ammonium hydroxide and at least one additional template.

The invention discloses a vanadium-modified iron-based activated carbon catalyst which comprises active components which are ferric oxide and vanadium pentoxide. Activated carbon serves as a carrier; the mass percentage of the vanadium pentoxide in the activated carbon is larger than 0 percent and smaller than or equal to 1 percent. The vanadium-modified iron-based activated carbon catalyst obtained by adding vanadium is excellent in low-temperature NH3-SCR (silicon controlled rectifier) activity and SO2 poisoning resistance; an operation temperature window is wide. Under 150 DEG C, the NOx purification efficiency of the catalyst is over 70 percent; under 175 DEG C, the NOx purification efficiency is over 80 percent; furthermore, under 200 DEG C, the catalyst is high in SO2 poisoning resistance.