Process for Elimination of Hexavalent Chromium Compounds on Metallic Substrates within Zero-PGM Catalyst Systems

摘要

Process for manufacturing ZPGM catalysts systems that may allow the prevention of formation or the conversion of corrosion causing compounds, such as hexavalent chromium compounds, within ZPGM catalyst systems is disclosed. In one embodiment, disclosed ZPGM catalysts systems, may include metallic substrate, which may include alloys of iron and chromium, a washcoat and an overcoat. Disclosed manufacturing process may include a thermal decomposition of hexavalent chromium compounds which may allow the decomposition of such compounds into trivalent chromium compounds, and may also produce metallic catalyst, such as silver. Such conversion may prevent corrosion formation, such as red color corrosion within ZPGM catalyst system. An embodiment of the disclosed process may include a reducing agent, which may be present in exhaust conditions, which may convert hexavalent chromium compounds into trivalent chromium compounds as well as produce metallic catalyst, such as silver. Employing the disclosed manufacturing process may allow the production of ZPGM catalyst systems that may exhibit high activity and enhanced performance.

主权项

1. A method for reducing corrosion of a catalytic system, comprising:
providing a catalyst system, comprising:
a substrate; anda washcoat suitable for deposition on the substrate, comprising at least one first oxide solid selected from the group consisting of a first carrier material oxide, at least one first catalyst, and a mixture thereof;wherein the washcoat is aged; and providing an exhaust stream having one selected from the group consisting of hydrogen, carbon monoxide, ammonia and combinations thereof.