Analysis on Properties and Failure Causes of Waste Exhaust Catalysts in Automobiles

Abstract:

There is a lack of comprehensive characterization of waste exhaust catalysts， resulting in an incomplete understanding of their physicochemical properties and causes of failures， which affects the recovery of platinum group metals from them. To this end， in this paper， a series of properties such as chemical composition and phases， surface elements， microscopic morphology， particle size， specific surface area and thermal stability were characterized and analyzed for waste exhaust catalysts. It is concluded that the failure causes mainly include sulfide and phosphide poisoning of platinum group metals， carbon adsorption on the catalyst surface， oxidation of platinum group metals， sintering agglomeration and packaging of platinum group metals in the substrate， reduction of specific surface area and total pore volume， etc.