A method for post-processing cu-ssz-13 molecular sieves synthesized in situ by one-pot method

Abstract

The invention belongs to the field of chemistry, and provided with a method used for post-treatment of on-pot in-situ synthesized Cu-SSZ-13 molecular sieve. The method comprises following steps: on-pot in-situ synthesized Cu-SSZ-13 molecular sieve is added into an alkali solution with a pH value of 7 to 10, stirring is carried out for 2 to 24h at 25 to 80 DEG C, washing filtering and drying are carried out so to obtain the Cu-SSZ-13 catalyst. The catalyst prepared using the method is excellent in low temperature activity, hydro-thermal stability, and metal poisoning resistance, is capable of adapting the complex strict working conditions in a diesel car post-treatment system, can be used for selectively catalytic reduction of nitrogen oxide (NOx) with ammonia gas in a diesel car post-treatment system for purifying of diesel car tail gas NOx; the weal alkali solution is adopted, requirements on reaction equipment are low, raw material sodium hydroxide or potassium hydroxide are easily available, low in cost, and convenient for transportation and storage, operation is safe, and the method is suitable for large scale industrial production.

Description

technical field [0001] The invention belongs to the field of chemistry and relates to a method for preparing a Cu-SSZ-13 catalyst, in particular to a method for preparing a Cu-SSZ-13 catalyst by post-processing a Cu-SSZ-13 molecular sieve synthesized in-situ by a one-pot method. Background technique [0002] Nitrogen oxides (NO x ), as a pollutant in industrial production and motor vehicle exhaust, is the culprit of photochemical smog, acid rain and smog. To meet increasingly stringent emission standards, NH 3 -SCR technology is widely used in the exhaust purification of diesel vehicles. [0003] V 2 O 5 -WO 3 (MoO 3 ) / TiO 2 As a common fixed source denitration catalyst, the catalyst has also been introduced into the purification of diesel vehicle exhaust. However, the catalyst has a narrow temperature window (300-400 °C), high SO 2 Oxidative and V 2 O 5 The biological toxicity limits its wide application. While other molecular sieve catalysts such as Cu-ZSM-5, C...

AI Technical Summary

Problems solved by technology

However, nitric acid, sulfuric acid, and hydrochloric acid in the report are all strong acids, which are highly oxidizing, corrosive, or irritating, and pose many safety hazards during transportation, storage, and use, and require high processing equipment

In the post-treatment process, the solution needs to be heated to 80°C, which is likely to cause the volatilization of the acid, which not only increases the production cost but also causes environmental pollution, which is not conducive to large-scale industrial production

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