Method for preparing diesel vehicle exhaust gas purification molecular sieve

Abstract

The invention relates to a method for preparing a diesel vehicle exhaust gas purification molecular sieve. The method comprises the following steps: (1) dissolving aluminum sulfate and manganese nitrate into deionized water, adding a template agent to the solution, further adding sodium hydroxide, performing stirring, adding silicon sol, and stirring the mixed gel so as to obtain a precursor solution; (2) crystallizing the precursor solution, filtering and washing the obtained solution, and performing drying and roasting so as to obtain an untreated molecular sieve; (3) sequentially adding ammonium nitrate, copper nitrate, chromium nitrate and cerium nitrate to the molecular sieve, performing ion exchange, and performing filtering, washing and drying so as to obtain an activated molecularsieve; and (4) adding samarium nitrate to the activated molecular sieve, performing ion exchange, and performing filtering, washing, drying and roasting, so as to obtain the diesel vehicle exhaust gaspurification molecular sieve. Defects of the prior art are overcome, a diesel vehicle exhaust gas is purified by using the molecular sieve, the hydrothermal stability and the low temperature activityof the molecular sieve can be improved, the toxicity of the molecular sieve can be degraded, thus being safe and environment-friendly.

Description

technical field [0001] The invention relates to the technical field of tail gas treatment, in particular to a method for preparing a molecular sieve for purifying diesel vehicle tail gas. Background technique [0002] Diesel vehicle exhaust pollution control is an international technical problem and research hotspot. At present, my country's diesel vehicle exhaust emission standards are National 4 and National 5 standards. Diesel vehicle exhaust has not yet been equipped with an exhaust after-treatment system. The key part of the exhaust gas purification after-treatment system is the catalytic converter. Except for a few imported vehicles, there is no diesel in my country. Industrial application of vehicle exhaust gas purification catalyst. With the development of the economy and the improvement of environmental requirements, my country is preparing to implement the National 6 standard. Once the National 6 standard is implemented, an after-treatment catalyst system must be i...

AI Technical Summary

Problems solved by technology

al 2 o 3 There have been a lot of research work on catalysts loaded with noble metals. This type of catalyst has good stability, but its catalytic activity is low, and it produces more reaction by-products. Another problem is that the temperature range with high activity is relatively low. Narrow, which is a key factor affecting the application of the catalyst

Titanium dioxide-supported vanadium-tungsten-titanium catalyst (V 2 o 5 / WO 3 / TiO 2 ) has better NH 3 -SCR activity, has become a commercial catalyst for NOx removal from stationary sources, but the low-temperature activity of the catalyst is poor, and V 2 o 5 Expensive and highly toxic

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