Preparation method of high-dispersed transition metal nanoparticle-supported hierarchical pore zeolite aggregate

Abstract

The invention discloses a preparation method of a high-dispersed transition metal nanoparticle-supported hierarchical pore zeolite aggregate. The preparation method comprises adding mixed liquid dropsof an inorganic aluminum source and a transition metal salt into an inorganic silicon source solution drop by drop, adjusting alkalinity through KOH or NaOH, carrying out stirring to obtain a transition metal-silica-alumina sol-gel solution, adding crystal gel with different crystal structures into the mixed solution, and carrying out crystallization at 80-200 DEG C for 10-48h to obtain the high-dispersed transition metal nanoparticle-supported hierarchical pore zeolite aggregate catalytic material with particle sizes of 1.5 to 2 nm. Compared with the prior art, the preparation method furthercontrols the synthesis of the hierarchical pore zeolite molecular sieve material, effectively adjusts and controls the opening degree of channels of hierarchical pore zeolite, and successfully modifies the surface of the hierarchical pore zeolite aggregate material with transition metal nanoparticles to produce the zeolite aggregate catalytic material with multiple active sites and agglomerationdifficulty. The preparation method has simple processes, is easy to operate and separate and has a certain industrial promotion use prospect and a remarkable economic value.

Description

technical field [0001] The invention relates to the technical field of synthesis of zeolite molecular sieves, in particular to the preparation of highly dispersed transition metal nanoparticle-loaded multi-stage zeolite aggregates. Background technique [0002] Nano-transition metal catalysts have received extensive attention and research because of their excellent catalytic performance, and have become one of the leading catalysts in modern chemical industry, and occupy a very key position in the field of catalysts. Because metal nanoparticles have high surface energy and are easy to agglomerate, making The activity is reduced. In order to solve this problem, highly active nanoparticles can be immobilized on the carrier, and the aggregation and inactivation of the nanoparticles can be inhibited by interacting with the carrier. [0003] Nanoparticle loading is mainly synthesized by impregnation. One is to synthesize the carrier first, then load the metal salt on the carrier ...

AI Technical Summary

Problems solved by technology

The patent (CN104858413 B) discloses a preparation method of silica-loaded noble metal nanoparticles, which adopts the inverse microemulsion method to mix 1-20 nm metal nanoparticles Cu, Au, Ni, Pt, Pd, Rh, Ir, Ru Silica particles loaded at 20-200 nm, the preparation requires the use of expensive reagents such as surfactants and long-chain fatty alcohols, and the preparation process is cumbersome

From the technical content disclosed in the above patent documents, it is not difficult to find that the preparation steps are very cumbersome, and the distribution of nanoparticles of the obtained materials does not clearly indicate the size of the particles.

[0005] To sum up, the transition metal nanoparticle catalysts supported by different molecular sieves prepared in the prior art generally need to synthesize zeolite molecular sieves first, and then carry out loading. The preparation steps are cumbersome, and agglomeration is easy to occur, resulting in larger particle sizes And uneven, greatly affecting the activity of transition metal supported catalysts

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