From Which National Emission Standard Did Cars Start Having Three-Way Catalytic Converters?
2 Answers
Three-way catalytic converters started being installed in cars from the National III emission standard. In earlier years, vehicles produced in China that did not meet the National II emission standard were not equipped with three-way catalytic converters. Composition of a Three-Way Catalytic Converter: A three-way catalytic converter is generally composed of four parts: the shell, vibration damping layer, substrate, and catalyst coating. Shell: Made of stainless steel to prevent the detachment of oxide scales, which could block the substrate. Vibration Damping Layer: Consists of a gasket or wire mesh pad, serving to seal, insulate, and secure the substrate. To protect the substrate from damage due to vibration, thermal deformation, and other factors, the gasket is made of expanded mica and aluminum silicate fibers, bonded together with adhesive. Substrate: Constructed from honeycomb-shaped ceramic materials, though many also use metal (including stainless steel) materials. Catalyst: Composed of precious metals such as platinum, rhodium, and palladium, sprayed onto the substrate to form the purifying agent. Lifespan of a Three-Way Catalytic Converter: The lifespan of a three-way catalytic converter is typically between 80,000 and 100,000 kilometers. The exact lifespan depends on the vehicle's usage conditions, as well as the quality of fuel used and the driving environment.
In all my years of driving, I recall that it was the China III emission standards that truly popularized the widespread installation of catalytic converters. Thinking back, that was around 2007 when the government mandated all new vehicles to be equipped with this device to improve air quality. During the China I and China II eras, many cars belched thick black smoke from their exhaust pipes, with very primitive emission treatment. After China III, catalytic converters helped oxidize harmful substances like carbon monoxide and hydrocarbons, making the air on the roads feel much fresher. However, these converters are prone to damage; poor fuel quality or extensive high-speed driving can cause them to burn out, and repairs aren’t cheap. I remember when buying a used car, I always checked the manufacturing year—if it was a post-2007 China III vehicle with a functioning catalytic converter, I felt more at ease; otherwise, it wouldn’t pass the annual inspection. Overall, China III was a milestone, making vehicles greener and pushing the automotive industry forward.
