The Development of a Zeolite-Based Cold-Start Catalyst (CSC) for a Conventional China 6b Vehicle in Meeting the Next More Stringent Chinese Vehicle Emission Standards

A state of art Pd-zeolite based cold-start catalyst (CSC) or HC/NOx trap type of catalyst was codeveloped between Geely Automotive Company and Ningbo Kesen Exhaust Gas Cleaner Manufacturing CO. LTD. This CSC catalyst was added to the downstream of an existing catalyst system (TWC+CGPF) of a China 6b conventional passage car which was powered by a 1.5L turbo charge direct injection (1.5L GTDI) engine. The CSC significantly converted cold-start tailpipe NMHC emission and enabled the tailpipe emissions to meet the engineering targets of the projected next more stringent Chinese vehicle tailpipe emission standards in WLTC cycles. The vehicle tailpipe emission results with the addition of the laboratory simulated 120K km aged CSC also met the projected emission engineering targets of a fresh catalyst.

Both the vehicle and laboratory results demonstrated the excellent ammonia adsorption and oxidation function of this CSC catalyst as a very efficient natural ammonia slip catalyst (ASC). Due to its independency of heating power (battery), CSC is a more cost-effective technology for both conventional and hybrid vehicles in converting both the tailpipe cold-start emissions (mainly NMHC) and eliminating ammonia slip over an aftertreatment system equipped with electrically heated catalyst (EHC) and an ASC catalyst for meeting the future Chinese low emission standards.