Encapsulated platinum-group subnano metal-supported porous titanium-silicon molecular sieve catalyst and its preparation and application

Abstract

The invention discloses an encapsulated platinum group subnano metal-loaded porous grade titanium-silicon molecular sieve catalyst and its preparation and application. The catalyst is that the subnano platinum group metal particles are evenly encapsulated in the pores of the porous grade HTS-1 molecular sieve, and the surface of the subnano platinum group metal particles has a metal oxide protective film; the platinum group metal is Pd, At least one of Pt, Ru, Au, in the catalyst, the silicon-titanium molar ratio of the porous grade HTS-1 molecular sieve is 20-2000, and the mass ratio of the subnanometer platinum group metal particles to the porous grade HTS-1 molecular sieve is 1 :100‑1:1000. The catalyst provided by the invention has strong sintering resistance, small metal size and uniform distribution, high metal utilization rate and eliminates lattice defects on the surface of metal particles. The invention provides the application of the encapsulated subnanometer platinum group metal particle-loaded porous titanium-silicon molecular sieve catalyst in the direct synthesis of hydrogen peroxide from hydrogen and oxygen, which can significantly increase the yield of hydrogen peroxide and realize the efficient utilization of precious metals , saving economic costs.

Description

technical field [0001] The invention belongs to the technical field of chemistry, and in particular relates to a porous-grade titanium-silicon molecular sieve-encapsulated subnano platinum group metal catalyst and its preparation and application in the direct synthesis of hydrogen peroxide from hydrogen and oxygen. [0002] technical background [0003] Hydrogen peroxide (also known as hydrogen peroxide) is an important chemical product, which is widely used in papermaking, textile, chemical, environmental protection, electronics, medicine and other industries. After hydrogen peroxide is decomposed, only water and oxygen are produced, which has no secondary pollution to the environment and belongs to green chemicals. With the strengthening of people's awareness of environmental protection and the continuous development of hydrogen peroxide applications, its market demand is increasing day by day. At present, there are five production methods of hydrogen peroxide: electrolysi...

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Problems solved by technology

However, the anthraquinone method still has many disadvantages: 1. The production process is complicated, the production equipment requires a large amount of funds, and the energy consumption is relatively large; 2. A large amount of organic matter and organic solvents are used in the reaction, which inevitably causes environmental pollution; 3. Production The occurrence of many side reactions in the process will lead to the degradation of the working fluid and the loss of the hydrogenation catalyst (multi-purpose supported Pd or Ni catalyst)

[0008] It is known from the above-mentioned prior art that the catalysts for directly synthesizing hydrogen peroxide from hydrogen and oxygen are all prepared by impregnation, and metal sintering is prone to occur during heat treatment or activation, resulting in excessive metal particle size, which is not conducive to the reaction and the metal utilization rate is not high.

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