A sapo-34 molecular sieve catalyst with ordered mesopores and preparation method thereof

Abstract

The invention relates to a SAPO‑34 molecular sieve catalyst with ordered mesopores and a preparation method thereof. The catalyst is formed by orderly stacking spherical SAPO‑34 molecular sieve nanoparticles with equal diameters, and the spherical SAPO‑34 molecular sieve nanoparticles with equal diameters Orderly stacking between them forms ordered mesopores and the pore size of mesopores can be regulated by changing the particle size of spherical SAPO‑34 molecular sieve nanoparticles. It has a highly regular ordered structure and multi-level channels on the nanoscale. It is used as methanol The preparation of catalysts for the reaction of low-carbon olefins can effectively accelerate the gas transfer rate, reduce mass transfer resistance, reduce the formation of carbon deposits and have strong carbon storage capacity. It can greatly extend the service life of the catalyst while maintaining the selectivity of olefins. The preparation method is simple, the cost is low, and it is suitable for industrial promotion.

Description

technical field [0001] The invention belongs to the technical field of molecular sieves, in particular to a SAPO-34 molecular sieve catalyst with ordered mesopores and a preparation method thereof. Background technique [0002] my country is a country poor in oil, low in gas, and relatively rich in coal. At present and for a long time to come, my country's energy structure will be dominated by coal resources. Among them, the coal-to-methanol process is one of the important ways for the efficient and clean conversion and utilization of coal. However, as of 2015, my country's annual total methanol production capacity has exceeded 60 million tons, and the annual consumption is less than 40 million tons. Serious overcapacity has emerged , the development of methanol refueling product processing technology has important practical significance. The technology of producing low-carbon olefins (MTO) from methanol is a key technology that can effectively alleviate the shortage of my c...

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Problems solved by technology

The synthesis and application of medium and micro double-hole SAPO-34 molecular sieves have been reported, and the synthesis methods mostly focus on in-situ synthesis and post-treatment methods. Patents CN102897794A, CN105152182A, and CN103523797A combine silicon sources, aluminum sources, phosphorus sources, and templates Mix with raw materials such as deionized water, and use the in-situ synthesis method to prepare and synthesize medium and micro double-hole SAPO-34 molecular sieves by controlling the nucleation and growth of molecular sieves. Although this method is simple and easy, the synthesized SAPO-34 The size of the mesopores of molecular sieves is difficult to control and forms a disordered structure; patents CN102923727A and CN104525250A prepare SAPO-34 molecular sieves with micropores, mesopores and macropores by acid and alkali post-treatment. 34 molecular sieves show high selectivity of low-carbon olefins in the MTO reaction process, but the acid or alkali treatment process of this method will cause a certain degree of damage to the acid structure and pore structure of SAPO-34 molecular sieves during the treatment process

At present, the preparation method of mesoporous double-pore SAPO-34 molecular sieve that can realize fine regulation of mesopore diameter has not been reported yet.

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