Method for synthesizing Cu-SSZ-13 molecular sieve catalyst by one step

Abstract

The invention relates to a method for synthesizing Cu-SSZ-13 molecular sieve catalyst by one step. The method is characterized by comprising the following steps: (1) mixing an organic amine template agent and deionized water; adding or not adding an NaOH aqueous solution; adding Cu-TEPA clathrate, and stirring evenly; adding an aluminum source and a silicon source, and stirring until all materials are mixed evenly; (2) placing a mixed solution obtained in step (1) into a stainless reaction still with a tetrafluoroethylene or para-polyphenylene lining; crystallizing the reaction still for 12 hours to 6 days at 100 to 200 DEG C.; (3) washing a crystallized product for a plurality of times until the solution is neutral; drying the obtained solid product in a drying oven for 5 to 12 hours at 60 to 150 DEG C; heating the dried solid to 500 to 600 DEG C. and roasting for 3 to 10 hours so as to obtain the Cu-SSZ-13 molecular sieve catalyst product. By adopting the method disclosed by the invention, the use amount of the N,N,N-trimethyl-1-ammonium adamantane template agent is greatly reduced, and the alkali metal ion content of the product is controlled, so that the hydrothermal aging property of the catalyst is optimized.

Description

technical field [0001] The invention relates to a one-step method for synthesizing a Cu-SSZ-13 molecular sieve catalyst, in particular to a one-step method for directly synthesizing a catalyst using a template agent mixture, and the catalyst is used as nitrogen oxide NO in diesel vehicle exhaust X Selective Catalytic Reduction. Background technique [0002] In recent years, air pollution has attracted more and more attention. Nitrogen oxides (NO X ) is an important cause of air pollution. NH 3 Selective catalytic reduction of NO X (NH 3 -SCR) is currently the most effective and mature diesel vehicle exhaust purification NO X One of the technical methods, the principle of which is based on NH 3 As a reducing agent, under the catalytic action of the catalyst, NO X Selective reduction to N 2 . Cu-CHA type molecular sieve catalysts have attracted extensive attention due to their excellent catalytic performance, good low temperature activity, high temperature resistance...

AI Technical Summary

Problems solved by technology

Xiao et al. used copper amine complex as a template to synthesize Cu-SSZ-13 molecular sieve catalyst in one step (Ren L. M. et al. Designed copper-amine complex as an efficient template for one-potsynthesis of Cu-SSZ-13 zeolite with excellent activity for selective catalytic reduction of NO X by NH 3 . Chem. Commun., 2011,47:9783; CN 102259892B), but it has the disadvantages of high and uncontrollable copper content, low Si / Al ratio (4-7), etc., which will greatly reduce the hydrothermal stability of the catalyst

At the same time, the invention patent application CN 104812469 A uses a simple combination of copper-polyamine complex and an additional organic molecule to act as a template to achieve a one-step synthesis of Cu-SSZ-13 molecular sieve catalyst. The example shows that it is used for the synthesis of N, The amount of N,N-trimethyl-1-adamantane ammonium template is relatively high (Si / OSDA is 0.1~0.7), because of the high cost of this template, it is not conducive to the industrial production of Cu-SSZ-13 catalyst

[0004] The content of alkali metal ions in the Cu-SSZ-13 catalyst has a great influence on the hydrothermal stability, too high content of alkali metal ions will lead to a decrease in the stability of Cu species in the catalyst, thereby reducing the hydrothermal stability of the catalyst

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