Molecular sieve confined noble metal catalyst for CO-SCR denitrification, preparation method and application thereof

A molecular sieve confined noble metal catalyst for CO-SCR denitrification, wherein the molecular sieve confined noble metal catalyst consists of a molecular sieve carrier and Ir metal nanoclusters loaded in the molecular sieve carrier through confined encapsulation;

• the molecular sieve carrier is an A-type molecular sieve, an X-type molecular sieve or a Y-type molecular sieve;
• a loading of the Ir metal nanoclusters in the molecular sieve confined noble metal catalyst is 0.1-1 wt. %;
• and a particle size of the Ir metal nanoclusters is ≤2 nm, and the Ir metal nanoclusters comprise an oxidized state of Irδ+ and a metallic state of Ir0, wherein a proportion of the Ir0 is 10-70 wt. %;
• wherein the molecular sieve confined noble metal catalyst is prepared by a method comprises the following steps:
• mixing a first metal precursor solution with a first ligand, and stirring to obtain a first mixed solution;
• mixing a second metal precursor solution with a second ligand, and stirring to obtain a second mixed solution;
• mixing silicon source, aluminum source, alkali and solvent, and stirring to obtain molecular sieve precursor solution;
• mixing the molecular sieve precursor solution with the first mixed solution and stirring, then adding the second mixed solution and stirring to obtain a third mixed solution;
• carrying out hydrothermal crystallization reaction on the third mixed solution, and after finishing the hydrothermal crystallization reaction, carrying out centrifugal washing, drying and calcining to obtain the molecular sieve confined noble metal catalyst for the CO-SCR denitrification;
• wherein
• the first metal precursor solution and the second metal precursor solution are both Ir salt solutions;
• and
• the first ligand is a C1-6 linear amine compound;
• the second ligand is alkoxy silane containing sulfhydryl or amino group.