Catalyst with active component nano particles embedded in molecular sieve to crystallize, method and application

Abstract

The invention discloses a catalyst with active component nano particles embedded in a molecular sieve to crystallize. The catalyst comprises metal active component nano particles and a molecular sieve, the catalyst comprises metal active component nano particles are embedded and dispersed in the molecular sieve, the content of the active component nano particles in the catalyst is 2-70wt%, the particle size of the active component nano particles is 4-200nm, the crystal grain size of the molecular sieve is 1-10mu m; and the invention further discloses a preparation method and an application of the catalyst. The active metal in the catalyst disclosed by the invention is embedded and dispersed in the molecular sieve, the particle size is small; the metal active centre is effectively matched with an acid centre, the heavy constituent product can be effectively cracked; the catalytic activity is high, the metal reducibility is high, and the methane selectivity is low; the Fischer-Tropsch reaction activity cannot be reduced; the preparation process is simple, the cost is recued, and the catalyst is suitable for large industrial application; and the molecular sieve cannot break due to the difference of thermal coefficients of expansion, and the mechanical strength is high.

Description

technical field [0001] The invention relates to a catalyst, a preparation method and its application; in particular, it relates to a catalyst, a method and an application in which active component nanoparticles are embedded in molecular sieve crystals. Background technique [0002] Under the background of the gradual scarcity of world oil resources and the increasingly prominent energy crisis, carbon-chemical (C 1 Chemistry) has been extensively researched and developed rapidly. The carbon chain growth process of synthesizing and preparing organic compounds containing two or more carbon atoms from compounds with only one carbon atom (such as CO, methane, methanol, hydrocyanic acid, etc.) is called carbon-one chemistry. Carbon-chemical raw materials have a wide range of sources, which can reduce the excessive dependence on petroleum resources. It is the most important and promising way to replace petroleum synthesis routes to prepare basic organic chemical raw materials, fue...

AI Technical Summary

Problems solved by technology

However, this type of supported catalyst has the following defects: 1) most of the active metals are located on the outer surface of the molecular sieve; 2) the particle size is large; 3) the metal active center and the acid center cannot be effectively matched, and the heavy component product cannot be effectively cracked; 4) due to the metal Strong interaction with molecular sieves, resulting in low catalytic activity, poor metal reduction, and high methane selectivity

However, such molecular sieve membrane catalysts have the following defects: 1) Generally, they are directly constructed on the surface of millimeter-scale nuclear catalysts, and the presence of molecular sieve membranes will increase CO and H 2 2) The preparation process of molecular sieve membranes is complex and often requires various pretreatment processes. The formation of molecular sieve membranes requires good compatibility between catalysts and molecular sieve membranes, and the film-forming properties are not easy to control. Defects such as cracks and pinholes are often formed; 3) During the process of removing the template agent by roasting the molecular sieve membrane, the molecular sieve membrane may be broken due to the difference in thermal expansion coefficient with the Fischer-Tropsch catalyst. Erosion can also cause a decrease in the mechanical strength of the catalyst

The catalysts used in traditional industries are rhodium-phosphine complexes, such as [Rh(CO)(TPPTS) 3 ][TPPTS=P(m-C 6 h 4 SO 3 Na) 3 ], etc., such catalysts are difficult to separate and recover from the liquid phase

In order to solve this problem, catalysts with active components immobilized have been developed in recent years, but it is difficult for such catalysts to obtain high selectivity for n-aldehydes, which have higher industrial application value

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