Hollow Cu-SSZ-13 molecular sieve catalyst and application thereof

Abstract

The invention discloses a preparation method of a Cu-SSZ-13 molecular sieve with a hollow structure and a method for selectively catalyzing NH3 to reduce NO. The preparation method comprises the following steps: firstly, performing one-step hydrothermal crystallization on gel formed by fully mixing a silicon source, an aluminum source, an inorganic alkali, a microporous template agent and an organic additive to directly prepare a hollow single crystal SSZ-13 molecular sieve; then respectively carrying out NH4 <+> and Cu <2+> ion exchange, centrifugal washing, drying and roasting to prepare a Cu-SSZ-13 molecular sieve with a hollow structure; and finally, under the catalytic action of the Cu-SSZ-13 molecular sieve with a hollow structure, selectively reducing NO into N2 by taking NH3 as a reducing agent. The SSZ-13 molecular sieve with the hollow structure is prepared through a one-step hydrothermal method, and compared with a traditional two-step acid-alkali treatment method, the SSZ-13 molecular sieve is more economical, simpler and more efficient; meanwhile, in the NO reduction reaction, mass transfer diffusion of all reaction molecules is facilitated, so that the NO reduction activity is effectively improved, the active window is widened, and the catalyst is more suitable for the NO reduction reaction under a high space velocity condition.

Description

technical field [0001] The invention relates to the removal of nitrogen oxide gas pollutants contained in fixed source flue gas such as boilers, incinerators, and exhaust gas from diesel vehicles, that is, the field of denitrification molecular sieve catalyst reaction, and specifically relates to the preparation of hollow Cu-SSZ-13 molecular sieve catalysts and apply. Background technique [0002] In recent years, as air pollution has become more and more serious, people have paid more and more attention to the emission of air pollutants. NO X It is clearly listed as a class of pollutants subject to total amount control. Its emission density is high and the emission is concentrated, causing serious harm. It is one of the most difficult pollutants to remove. During the operation of diesel vehicles, a large amount of NO will be produced X , causing serious air pollution. NH 3 Selective Catalytic Reduction of NO X (NH 3 -SCR) is a mature and effective diesel vehicle exha...

AI Technical Summary

Problems solved by technology

However, the traditional hollow structure is mainly through two-step acid-base treatment method, the procedure is complicated, the cost is high, and the molecular sieve structure is easy to be damaged.

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