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CN-121972173-A - Rare earth element Ho modified Ni-based catalyst and preparation method and application thereof

CN121972173ACN 121972173 ACN121972173 ACN 121972173ACN-121972173-A

Abstract

The invention relates to a rare earth element Ho modified Ni-based catalyst, a preparation method and application thereof, wherein the rare earth element Ho modified Ni-based catalyst comprises an active component and an auxiliary agent, the active component is NiO, the auxiliary agent is Ho 2 O 3 , and the element mole ratio of Ho to Ni in the rare earth element Ho modified Ni-based catalyst is (0.002-0.008): 1. According to the invention, by introducing the auxiliary agent Ho 2 O 3 and regulating the element molar ratio of Ho to Ni in the rare earth element Ho modified Ni-based catalyst to be (0.002-0.008): 1, on one hand, the specific surface area and pore volume of NiO can be increased, the average pore diameter can be reduced, the exposure of active sites can be promoted, and on the other hand, edge dislocation and defect structures can be induced to form, thereby being beneficial to the generation of oxygen vacancies and further improving the catalytic performance.

Inventors

  • LIAN ZHIHUA
  • CHEN HAO
  • SHENG JIAXIN
  • ZHOU XUENING
  • SHAN WENPO
  • HE HONG

Assignees

  • 中国科学院城市环境研究所

Dates

Publication Date
20260505
Application Date
20260209

Claims (10)

  1. 1. The rare earth element Ho modified Ni-based catalyst is characterized by comprising an active component and an auxiliary agent, wherein the active component is NiO, and the auxiliary agent is Ho 2 O 3 ; the molar ratio of Ho to Ni in the rare earth element Ho modified Ni-based catalyst is (0.002-0.008): 1.
  2. 2. The rare earth element Ho-modified Ni-based catalyst according to claim 1, wherein Ho 2 O 3 is distributed on the NiO surface.
  3. 3. The rare earth element Ho-modified Ni-based catalyst according to claim 1 or 2, characterized in that the specific surface area of the rare earth element Ho-modified Ni-based catalyst is 30m 2 /g~60m 2 /g; Preferably, the pore volume of the rare earth element Ho modified Ni-based catalyst is 0.15cm 3 /g~0.30cm 3 /g; preferably, the average pore diameter of the rare earth element Ho modified Ni-based catalyst is 10 nm-20 nm.
  4. 4. A method for preparing the rare earth element Ho-modified Ni-based catalyst according to any one of claims 1 to 3, comprising the steps of: Mixing Ni source and Ho source to obtain mixed solution, adding precipitant into the mixed solution, ageing to obtain catalyst precursor, and roasting the catalyst precursor to obtain the rare earth element Ho modified Ni-based catalyst.
  5. 5. The method of claim 4, wherein the Ni source comprises any one or a combination of at least two of nitrate, sulfate, chloride, or carbonate of Ni; Preferably, the Ho source comprises any one or a combination of at least two of nitrate, sulfate, chloride or carbonate of Ho; preferably, the temperature of the mixing is 20-50 ℃; preferably, the mixing time is 1-5 h; Preferably, the mixing is performed under stirring conditions; preferably, the stirring speed is 400 r/min-800 r/min.
  6. 6. The method according to claim 4 or 5, wherein the precipitant comprises any one or a combination of at least two of ammonium carbonate solution, ammonium bicarbonate solution, sodium carbonate solution, or sodium bicarbonate solution; preferably, the concentration of the precipitant is 1.5 mol/L-2.5 mol/L; preferably, the precipitant is added dropwise; Preferably, the dropwise adding speed is 2 s/drop-4 s/drop; Preferably, the addition of the precipitant is carried out with stirring; preferably, the stirring speed is 400 r/min-800 r/min; Preferably, the precipitant adjusts the pH of the mixed solution to 8-10.
  7. 7. The method according to any one of claims 4 to 6, wherein the aging time is 12 to 24 hours; Preferably, the aging process further comprises filtering, washing and drying to obtain a catalyst precursor; Preferably, the washing comprises washing until the pH of the filtrate is 6.5-7.5; Preferably, the drying temperature is 80-120 ℃; preferably, the drying time is 12-24 hours.
  8. 8. The method according to any one of claims 4 to 7, wherein the baking temperature is 300 ℃ to 500 ℃; Preferably, the roasting time is 2-6 hours.
  9. 9. The production method according to any one of claims 4 to 8, further comprising tabletting, grinding and sieving the rare earth element Ho-modified Ni-based catalyst; Preferably, the sieving comprises sieving the rare earth element Ho modified Ni-based catalyst with a 40-mesh sieve, collecting undersize, sieving with a 60-mesh sieve, and collecting oversize to obtain the 40-mesh to 60-mesh rare earth element Ho modified Ni-based catalyst.
  10. 10. The use of a rare earth element Ho-modified Ni-based catalyst according to any one of claims 1 to 3, wherein the rare earth element Ho-modified Ni-based catalyst is used for direct catalytic decomposition of N 2 O.

Description

Rare earth element Ho modified Ni-based catalyst and preparation method and application thereof Technical Field The invention belongs to the technical field of catalysts, and relates to a Ni-based catalyst, in particular to a rare earth element Ho modified Ni-based catalyst, and a preparation method and application thereof. Background Nitrous oxide (N 2 O) is a strong greenhouse gas with a much higher heating potential than CO 2 and CH 4, and is also the main substance consuming stratospheric ozone. The artificially discharged N 2 O mainly comes from fossil fuel combustion, chemical process, automobile exhaust emission and the like. Scientists have predicted that the emission of N 2 O would increase to twice the current level in 2050 if left uncontrolled. Therefore, development and innovation of N 2 O degradation technology are imperative. The existing N 2 O degradation technology comprises a high-temperature decomposition method, a selective catalytic reduction method and a direct catalytic decomposition method. The direct catalytic decomposition method has the advantages of simple operation, high cracking efficiency, low energy consumption, no secondary pollution and the like, and the core of the direct catalytic decomposition method is to efficiently and selectively catalyze and decompose N 2 O into nontoxic and harmless N 2 and O 2 by means of a catalyst. The catalyst of the N 2 O direct catalytic decomposition method mainly comprises a noble metal catalyst, a molecular sieve catalyst and a metal oxide catalyst. Among them, the metal oxide catalyst exhibits excellent catalytic activity in direct catalytic decomposition of N 2 O due to its unique structure and abundant oxygen defects. CN115430453a discloses a transition metal oxide catalyst for low-temperature catalytic decomposition of N 2 O, and a preparation method and application thereof, which is obtained by acid treatment and calcination of a transition metal oxide substrate, wherein the conversion rate of N 2 O of the Co 3O4 -N catalyst at 350 ℃ is approximately 60%, and the corresponding temperature (T90) at which the conversion rate of N 2 O is 90% is 375 ℃. CN117101667a discloses a catalyst for low-temperature catalytic decomposition of N 2 O, a preparation method, an activation method and an application thereof, which takes rare earth metal oxide as an auxiliary agent, and explores the effect of improving the catalytic performance of the catalyst in the molar ratio of rare earth metal element to transition metal element within the range of 0.01:1-0.1:1, wherein the doping of rare earth elements Yb, gd and Pr improves the catalytic activity of the catalyst, while the doping of rare earth elements Tb, lu, er and Ho reduces the catalytic activity of the catalyst. Transition metal oxide catalysts require higher temperatures to decompose N 2 O effectively, but lower activities at lower temperatures. In addition, the activities of the NiO catalyst are inhibited by the impurity gases such as NO, O 2, H 2 O and the like, so that the catalyst performance is reduced or even deactivated. Therefore, providing a nickel-based catalyst with good low-temperature activity and strong resistance to impurity gases is a problem to be solved in the current field. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a rare earth element Ho modified Ni-based catalyst, and a preparation method and application thereof. According to the invention, by introducing the auxiliary agent Ho 2O3 and regulating the element molar ratio of Ho to Ni in the rare earth element Ho modified Ni-based catalyst to be (0.002-0.008): 1, on one hand, the specific surface area and pore volume of NiO can be increased, the average pore diameter can be reduced, the exposure of active sites can be promoted, and on the other hand, edge dislocation and defect structures can be induced to form, thereby being beneficial to the formation of oxygen vacancies and further improving the catalytic performance. In order to achieve the aim of the invention, the invention adopts the following technical scheme: In a first aspect, the invention provides a rare earth element Ho modified Ni-based catalyst, which comprises an active component and an auxiliary agent, wherein the active component is NiO, and the auxiliary agent is Ho 2O3. The molar ratio of Ho to Ni in the rare earth element Ho modified Ni-based catalyst is (0.002-0.008): 1, for example, 0.002:1, 0.003:1, 0.004:1, 0.005:1, 0.006:1, 0.007:1, 0.008:1, or the like. According to the invention, by introducing the auxiliary agent Ho 2O3 and regulating the element molar ratio of Ho to Ni in the rare earth element Ho modified Ni-based catalyst to be (0.002-0.008): 1, on one hand, the specific surface area and pore volume of NiO can be increased, the average pore diameter can be reduced, the exposure of active sites can be promoted, and on the other hand, edge dislocation and defect structures can be induced