Low-temperature denitration catalyst and preparation method thereof
阅读说明：本技术 一种低温脱硝催化剂及其制备方法 (Low-temperature denitration catalyst and preparation method thereof ) 是由 陈镖 于 2019-08-28 设计创作，主要内容包括：一种低温脱硝催化剂及其制备方法,该催化剂包括采用铈、钙和锶元素掺杂的锰酸镧组分和助剂；所述助剂为氧化锰和碳酸钙的混合物。通过四价的铈或者三价和四价的混合铈、钙和或锶离子的掺杂获得了锰酸镧组分,并通过其与氧化锰、碳酸钙进行机械复合,得到一种复合催化剂,具有长效抗硫性能,适合在低温下催化CO的氧化和NO的还原反应,同时也能够在O<Sub>2</Sub>参与的情况下维持较高的脱硝率,使用寿命长。(A low-temperature denitration catalyst and a preparation method thereof, wherein the catalyst comprises a lanthanum manganate component and an auxiliary agent which are doped by cerium, calcium and strontium elements; the auxiliary agent is a mixture of manganese oxide and calcium carbonate. The lanthanum manganate component is obtained by doping tetravalent cerium or trivalent and tetravalent mixed cerium, calcium and/or strontium ions, and is mechanically compounded with manganese oxide and calcium carbonate to obtain the composite catalyst which has long-acting sulfur resistance and is suitable for catalyzing the oxidation of CO and the reduction of NO at low temperatureCan also react at the same time as O 2 The high denitration rate is maintained under the participation condition, and the service life is long.)
1. a kind of low-temperature denitration catalyst, it is characterised in that it include using cerium, calcium and strontium element doping lanthanum manganate component and Auxiliary agent；The auxiliary agent is the mixture of manganese oxide and calcium carbonate, and Ce elements are in lanthanum manganate component relative to the quality of lanthanum element Degree is x, and calcium constituent is y relative to the mass percentage content of lanthanum element in lanthanum manganate component, and strontium element is in manganese In sour lanthanum component relative to the mass percentage content of lanthanum element be z, wherein x not less than 8.0%, y not less than 1.6%, z it is not small In 0%, and the range of x+y+z is 12%-94%.
2. a kind of low-temperature denitration catalyst as described in claim 1, it is characterised in that in the catalyst, lanthanum manganate component Mass parts are 10, and the mass parts of auxiliary agent are 1.
3. a kind of low-temperature denitration catalyst as claimed in claim 2, it is characterised in that in the auxiliary agent, the quality of manganese oxide Part is 0.23, and the mass parts of calcium carbonate are 0.77.
4. a kind of low-temperature denitration catalyst as described in claim 1, it is characterised in that Ce elements are four in lanthanum manganate component Valence cerium, or the mixing cerium for trivalent and tetravalence.
5. a kind of preparation method of low-temperature denitration catalyst as described in claim 1, it is characterised in that itself the following steps are included:
S1: by La (NO3)3·6H2O, the Mn (NO that mass percent concentration is 50.0%3)2Solution and cerium source, calcium source and barium source are molten Yu Shuizhong forms solution；
S2: under room temperature and stirring, citric acid and cellulose are added in solution, form gel；
S3: gel obtained in S2 being placed under the conditions of 95 DEG C and continues to heat, and removes the volatile matters such as solvent；
S4: after grinding, in air atmosphere under the conditions of 700 DEG C 5 hours of calcination, after being cooled to room temperature, mangaic acid can be obtained Lanthanum component；
S5: lanthanum manganate component, manganese oxide and calcium carbonate ball milling 2 hours are obtained into catalyst.
6. a kind of preparation method of low-temperature denitration catalyst as described in claim 1, it is characterised in that in step sl, cerium source For Ce (NH4)2(NO3)6With Ce (NO3)3·6H2O, calcium source is Ca (NO3)2·4H2O, barium source are Sr (NO3)2·4H2O。
7. a kind of preparation method of low-temperature denitration catalyst as described in claim 1, it is characterised in that each group in step sl Point additional amount is respectively as follows: the La (NO that mass parts are 21.6-38.13)3·6H2O, the mass percent concentration that mass parts are 35.8 For 50.0%Mn (NO3)2Solution, mass parts are the Ce (NH of 3.8-13.64)2(NO3)6, mass parts are the Ce (NO of 0-8.83)3· 6H2O, mass parts are the Ca (NO of 1.2-10.13)2·4H2Sr (the NO that O and mass parts are 0-8.03)2·4H2O is dissolved in mass parts For in 200.0 water.
8. a kind of preparation method of low-temperature denitration catalyst as described in claim 1, it is characterised in that in step s 2, be added The mass parts of citric acid are 25.3, and the mass parts that cellulose is added are 0.15.
9. a kind of preparation method of low-temperature denitration catalyst as described in claim 1, it is characterised in that in step s 5, mangaic acid The mass parts of lanthanum component are 10, and the mass parts of manganese oxide are 0.23, and the mass parts of calcium carbonate are 0.77.
10. a kind of preparation method of low-temperature denitration catalyst as described in claim 1, it is characterised in that in step s3, institute The time for stating gel heating evaporation is 4 hours.
Technical field
The present invention relates to catalyst technical fields more particularly to a kind of low-temperature denitration catalyst and preparation method thereof.
Background technique
As dynamics of the China to air contaminant treatment continues to increase, reduces nitrogen oxides in effluent discharge and have become The important issue of industry.Denitration, as the term suggests being exactly to detach nitre, current there are mainly two types of denitrating techniques, first is that SCR, i.e. selective catalytic reduction；Another kind is SNCR, i.e. selective non-catalytic reduction method.Wherein the former is usually 300 Denitration is carried out under the conditions of DEG C -400 DEG C, is the denitration technology research direction of our times mainstream, and the denitration that development is most mature Technology；The latter usually carries out denitration under the conditions of flue-gas temperature is 850 DEG C -1100 DEG C.Belong to denitration after furnace from process Technology, when effect, need the reducing agents such as oxygenous, catalyst and ammonia, urea the NOx in flue gas could be reduced into N2And water.
But the temperature that traditional SCR denitration technology carries out, mostly at 300 degrees Celsius or more, this requires catalyst In the environment that high temperature must be arranged in arrangement, however in reality, there are a large amount of dust etc. in the placement ground of catalyst Object is very easy to catalyst poisoning occur.It is influenced simultaneously by historical factor, its position is not reserved in China's fired power generating unit yet It sets；In addition, the coal-fired overall quality in China is not high, the device and catalyst of SCR are seriously compromised.And low temperature SCR denitration technology Carry out temperature at 300 degrees Celsius hereinafter, can effectively solve the problem that above-mentioned traditional SCR denitration technology there are the problem of.And for Stationary source denitrating flue gas, under the flue-gas temperature lower than 300 DEG C of ranges, the problem of being also faced with flue gas complexity, such as: flue gas In there are NO, O2Or contain NO, O simultaneously2And CO.
LaMnO3 is a kind of catalyst with perovskite structure, and the doping vario-property of location A can be to its defect structure It makes, oxygen defect and B location atomic valence etc. are regulated and controled, this to regulate and control the chemical activity of O is caused to improve and provide coordination position Point.Such as: CO is reacted with catalysis of the NO on perofskite type oxide may relate to: the lattice on CO molecule abstracts perovskite The Lacking oxygen of oxygen, generation has been improved the chemisorption of NO, in turn results in CO and is oxidized to CO2N is reduced into NO2(Yuxin Wen, et al., Catalytic oxidation of nitrogen monoxide over La1-xCexCoO3 perovskites,Catalysis Today, 2007,126(3-4):400-405；Steenwinkel Y Z, et al. .Step response and transient isotopic labeling studies into the mechanism of CO oxidation over La0.8Ce0.2MnO3 perovskite,Applied Catalysis B:Environmental, 2004,54,93-103)。
Summary of the invention
Shortcoming present in view of the above technology, the present invention provide a kind of low-temperature denitration catalyst, which is A kind of composite catalyst has long-acting sulfur resistance, is suitble to be catalyzed the oxidation of CO and the reduction reaction of NO at low temperature, simultaneously It also can be in O2Higher denitrification rate is maintained in the case where participation, service life is longer.
It is a further object to provide a kind of preparation method of low-temperature denitration catalyst, by the cerium of tetravalence or The doping of the mixing cerium, calcium and/or strontium ion of person's trivalent and tetravalence obtains lanthanum manganate component, and passes through itself and manganese oxide, carbon Sour calcium progress is mechanical compound, a kind of low-temperature denitration of flue gas catalyst can be obtained, preparation method is simple.
To achieve the above object, the present invention is implemented as follows:
A kind of low-temperature denitration catalyst, it is characterised in that it includes the lanthanum manganate component using cerium, calcium and strontium element doping And auxiliary agent；The auxiliary agent is the mixture of manganese oxide and calcium carbonate, and Ce elements are in lanthanum manganate component relative to the matter of lanthanum element Amount degree is x, and calcium constituent is y relative to the mass percentage content of lanthanum element in lanthanum manganate component, and strontium element exists In lanthanum manganate component relative to the mass percentage content of lanthanum element be z, wherein x not less than 8.0%, y be not less than 1.6%, z Not less than 0%, and the range of x+y+z is 12%-94%.
Further, in the catalyst, the mass parts of lanthanum manganate component are 10, and the mass parts of auxiliary agent are 1.
Further, in the auxiliary agent, the mass parts of manganese oxide are 0.23, and the mass parts of calcium carbonate are 0.77.
Further, Ce elements are quadrivalent cerium, or the mixing cerium for trivalent and tetravalence in lanthanum manganate component.
A kind of preparation method of low-temperature denitration catalyst, it is characterised in that itself the following steps are included:
S1: by La (NO3)3·6H2O, the Mn (NO that mass percent concentration is 50.0%3)2Solution and cerium source, calcium source and Barium source formation solution soluble in water；
S2: under room temperature and stirring, citric acid and cellulose are added in solution, form gel；
S3: gel obtained in S2 being placed under the conditions of 95 DEG C and continues to heat, and removes the volatile matters such as solvent；
S4: after grinding, in air atmosphere under the conditions of 700 DEG C 5 hours of calcination, after being cooled to room temperature, can be obtained Lanthanum manganate component；
S5: lanthanum manganate component, manganese oxide and calcium carbonate ball milling 2 hours are obtained into catalyst.
Further, in step sl, cerium source is Ce (NH4)2(NO3)6With Ce (NO3)3·6H2O, calcium source is Ca (NO3)2· 4H2O, barium source are Sr (NO3)2·4H2O。
Further, each component additional amount is respectively as follows: the La (NO that mass parts are 21.6-38.1 in step sl3)3· 6H2O, the mass percent concentration that mass parts are 35.8 are 50.0%Mn (NO3)2Solution, mass parts are the Ce of 3.8-13.6 (NH4)2(NO3)6, mass parts are the Ce (NO of 0-8.83)3·6H2O, mass parts are the Ca (NO of 1.2-10.13)2·4H2O and matter Measure the Sr (NO that part is 0-8.03)2·4H2O is dissolved in the water that mass parts are 200.0.
Further, in step s 2, the mass parts that citric acid is added are 25.3, and the mass parts that cellulose is added are 0.15.
Further, in step s 5, the mass parts of lanthanum manganate component are 10, and the mass parts of manganese oxide are 0.23, calcium carbonate Mass parts be 0.77.
Further, in step s3, the time of the gel heating evaporation is 4 hours.
It is an advantage of the present invention that mixing by the cerium of tetravalence or the mixing cerium of trivalent and tetravalence, calcium and/or strontium ion It is miscellaneous to obtain lanthanum manganate component and mechanical compound with manganese oxide, calcium carbonate progress by it, a kind of composite catalyst is obtained, is had There is long-acting sulfur resistance, is suitble to be catalyzed the oxidation of CO and the reduction reaction of NO at low temperature, while also can be in O2The feelings of participation Higher denitrification rate, long service life are maintained under condition.
Specific embodiment
In order to make the objectives, technical solutions, and advantages of the present invention clearer, with reference to embodiments, to this hair It is bright to be further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, not For limiting the present invention.