CN-121988342-A - Anti-reducing atmosphere Ni-based monoatomic catalyst and preparation method and application thereof

CN121988342ACN 121988342 ACN121988342 ACN 121988342ACN-121988342-A

Abstract

The invention discloses a reducing atmosphere resistant Ni-based monoatomic catalyst and a preparation method and application thereof, and belongs to the technical field of monoatomic catalyst preparation. The preparation method comprises the steps of preparing Ni salt solution, namely dissolving Ni salt in water, carrying out ultrasonic auxiliary dissolution at room temperature to obtain uniform Ni salt solution, loading the Ni salt on a carrier, namely weighing a MnO carrier, loading the uniform Ni salt solution on the MnO carrier by adopting an equal-volume impregnation method, then carrying out vacuum drying on a sample, and preparing the anti-reducing atmosphere Ni-based monoatomic catalyst, namely placing the dried sample in a calciner, heating to a calcination temperature, carrying out constant-temperature calcination, and fully grinding the sample after the calcination is completed to obtain the MnO-loaded Ni monoatomic catalyst, namely the anti-reducing atmosphere Ni-based monoatomic catalyst. The catalyst disclosed by the invention has the advantages of simple preparation process, low cost, environment friendliness, excellent stability, obvious technical advantages and application value, and has industrial popularization potential.

Inventors

ZHANG NINGQIANG
ZHAO JINSHENG
LI ZHAOHUI
ZHANG ZHAORUI
HAN XIAO
HAN JIANAN

Assignees

东北大学
聊城大学

Dates

Publication Date: 20260508
Application Date: 20260202

Claims (10)

1. The preparation method of the anti-reducing atmosphere Ni-based monoatomic catalyst is characterized by comprising the following steps of: preparing Ni salt solution, namely dissolving Ni salt in water, and carrying out ultrasonic auxiliary dissolution at room temperature to obtain uniform Ni salt solution; The Ni salt is loaded on the carrier, namely weighing the MnO carrier, loading the uniform Ni salt solution on the MnO carrier by adopting an isovolumetric impregnation method, and then carrying out vacuum drying on the sample; And (3) preparing the anti-reducing atmosphere Ni-based monoatomic catalyst, namely placing the dried sample in a calciner, heating to a calcination temperature, calcining at a constant temperature, and fully grinding the sample after the calcination is completed to obtain the MnO-loaded Ni monoatomic catalyst, namely the anti-reducing atmosphere Ni-based monoatomic catalyst.
2. The method for preparing a reducing atmosphere resistant Ni-based monoatomic catalyst according to claim 1, wherein the Ni salt is one or more of nickel nitrate, nickel chloride and nickel carbonate.
3. The method for preparing a reduction atmosphere Ni-based monoatomic catalyst according to claim 1, wherein the amount of Ni salt added is adjusted based on the Ni content of the reduction atmosphere Ni-based monoatomic catalyst of 0.5wt.% to 1.5wt.% in the Ni salt solution.
4. The method for preparing a reduction atmosphere resistant Ni-based monoatomic catalyst according to claim 1, wherein Ni salt is loaded into the carrier, and the vacuum drying is performed at a temperature of 100 ℃ to 200 ℃ for a period of 1h to 5h.
5. The method for preparing the anti-reducing atmosphere Ni-based monoatomic catalyst according to claim 1, wherein in the preparation of the anti-reducing atmosphere Ni-based monoatomic catalyst, the heating rate is 2 ℃ per minute to 8 ℃ per minute, the calcining temperature is 300 ℃ to 700 ℃, and the constant-temperature calcining time is 2h to 8h.
6. A reduction atmosphere resistant Ni-based monoatomic catalyst prepared by the method of any one of claims 1 to 5.
7. Use of the reducing atmosphere resistant Ni-based monoatomic catalyst of claim 6 in hydrogenation reactions.
8. The use of the anti-reducing atmosphere Ni-based monoatomic catalyst according to claim 7 in hydrogenation reactions, wherein the catalyst is applied to thermocatalytic and photo-thermocatalytic reverse steam shift reactions.
9. The use of the reduction atmosphere Ni-based monoatomic catalyst of claim 8 for hydrogenation reactions wherein Ni is highly dispersed and uniformly distributed in the H 2 atmosphere and is present as monoatoms on the MnO support surface.
10. The use of the reduction atmosphere resistant Ni-based monoatomic catalyst according to claim 8 for hydrogenation reactions, characterized in that the CO yield in the photo-thermal catalytic reverse steam shift reaction of 350 o C、1.5W/cm 2 is 9.88 mmol/(g·h) and the CO selectivity is 99%.

Description

Anti-reducing atmosphere Ni-based monoatomic catalyst and preparation method and application thereof Technical Field The invention belongs to the technical field of monoatomic catalyst preparation, and particularly relates to a reducing atmosphere resistant Ni-based monoatomic catalyst, and a preparation method and application thereof. Background Monoatomic catalysts are favored in various chemical transformations because they maximize the utilization of metal atoms and unique electronic structures. Especially in selective hydrogenation reactions, the single-atom catalysts represent a unique advantage in terms of adjusting the selectivity of the product, which is of great importance for the development of green catalytic processes. Environmental problems caused by excessive consumption of fossil energy are increasingly remarkable, and emission reduction and resource utilization of CO 2 become research hot spots in the field of energy chemical industry. The reverse steam shift Reaction (RWGS) is used as a key bridge technology for CO 2 conversion and utilization, and can convert low-added-value CO 2 and a hydrogen source (especially renewable energy sources for preparing green hydrogen) into high-added-value CO, so that the recycling closed loop of 'CO 2 - & gtCO- & gthigh-value products' is realized, green hydrogen is effectively consumed, renewable energy sources and a traditional chemical system are connected, and the low-carbon conversion of an energy structure is pushed. In the RWGS reaction system, the catalyst is a core factor for determining the reaction efficiency, the product selectivity and the industrialization feasibility, the RWGS reaction needs to break through thermodynamic limitation under a specific temperature condition, and the risk of side reactions such as CH 4 and the like is caused by excessive hydrogenation of CO, so that the optimization of the catalyst type and structure becomes a key for promoting the industrialized application of the reverse water vapor shift reaction. At present, the single-atom catalyst suitable for hydrogenation reaction and RWGS reaction is mainly divided into two major types of noble metal single-atom catalyst and non-noble metal single-atom catalyst, wherein the noble metal single-atom catalyst has the advantages of high reaction activity, low activation energy, rare noble metal reserves, high price, difficult bearing of cost pressure of large-scale industrial application, and complex preparation process due to the fact that part of high-performance noble metal single-atom catalyst depends on special carriers or auxiliary agents for modification, and further the universality and the industrialized popularization of the noble metal single-atom catalyst are limited. Among the non-noble metal monoatomic catalysts, the Ni-based monoatomic catalyst has both performance potential and cost advantages, but there are still a plurality of problems to be solved urgently, such as insufficient catalytic activity of the original Ni-based monoatomic catalyst, improved process stability and the like. Under the high temperature and reducing atmosphere, the metal single atoms are easy to generate dynamic structure evolution, and if the metal-carrier interaction is improperly regulated, atom migration agglomeration is easy to occur, so that active sites are lost. In the prior art, reducible metal oxides such as Fe 2O3、Co3O4、CeO2 and the like are generally adopted as metal monoatomic catalyst carriers, the interaction between the carriers and metal monoatoms is utilized in the catalytic reaction to realize the improvement of catalytic performance, and meanwhile, the coordination environment determined by monoatomic sites is utilized to improve the selectivity of a reaction path and promote the realization of accurate catalysis. However, under the conditions of reducing atmosphere such as H 2 and CO and higher temperature of a RWGS reaction system, high-valence reducible oxides such as Fe 2O3、Co3O4、CeO2 are used as carriers, irreversible crystal phase transition from high valence state to low valence state can occur, the anchoring sites of metal single atoms are destroyed, single atoms are separated from a coordination environment, the surface energy of the isolated metal single atoms is higher, migration and agglomeration are easy to occur, nano particles are formed, and the single-atom catalyst loses active centers of atomic-level dispersion. Therefore, the Ni-based monoatomic catalyst is not preferable to use Fe 2O3、Co3O4、CeO2 as a carrier. How to select a proper carrier, a Ni-based monoatomic catalyst which has simple preparation process, low cost, even dispersion of active sites, high activity, high selectivity and long-term stability is developed, and the problem to be solved in the prior art is urgent. Disclosure of Invention Aiming at the problems existing in the prior art, the invention aims to provide a reducing atmosphere resistant Ni-based single-atom catalyst and a