| The effects of temperature, gas flow rate, air-fuel ratio and different degrees of deterioration on the oxygen storage capacity (OSC) of three-way catalysts were investigated on a gasoline engine bench testing platform. The results show that increasing the temperature can accelerate the chemical reaction, thereby improving OSC, while increasing the gas flow rate will elevate the space velocity of the reaction and shorten the residence time of the exhaust gases within the catalyst pores, lowering OSC. Expansion of the air-fuel ratio window leads to an increase in the concentration of gas pollutants, which is beneficial to the chemical reaction between the active components of the catalyst and the oxygen storage material, as a result an improved OSC has been realized. Under the conditions of variable temperatures and flow rates, OSC will be improved by increasing the temperature, but increasing the gas flow rate will suppress OSC, consequently OSC rises more smoothly for a fresh catalyst, compared with the situation at a constant flow rate and temperature. The active states of the catalyst are determined by thermal aging temperature and time, and the catalytic activity will deteriorate significantly with the increase of aging temperature and time. |
