Synthesis of Cu/SAPO-34 with variable copper loadings

摘要

A Cu-amine complex of hydrated copper sulfate and ethylene diamine or an oligomer of ethylene diamine is employed in a direct (one-pot) synthesis of a copper-cation containing silicoaluminophosphate (SAPO) zeolite material having the Cu/SAPO-34 structure. The copper-amine complex is included in an aqueous gel of precursors of the SiO2, Al2O3, and P2O5 constituents, which are mixed, aged, and thermally treated to form the desired Cu/SAPO-34 structure. The synthesized Cu/SAPO-34 material is demonstrated to be an effective catalyst material in conversion of nitric oxide to nitrogen (using ammonia as a reductant) in synthetic exhaust streams characteristic of diesel engine and other lean-burn vehicle engine exhaust streams.

主权项

1. A method of forming Cu/SAPO-34 comprising:
forming an aqueous gel of Al2O3 or a Al2O3 precursor, P2O5 or a P2O5 precursor, and SiO2 or a SiO2 precursor; adding to the aqueous gel, or forming in the aqueous gel, a water soluble amine complex of copper in its +2 oxidation state and an equal molar amount of ethylene diamine or an oligomer of ethylene diamine, the copper being provided by a water soluble copper salt; stirring and aging the gel without heating; heating the gel to form a solid product; and calcining the solid product to form a crystalline product with SAPO-34 crystal structure containing copper +2 cations enclosed within the crystal structure.