Experimental and simulation investigation on the different iron content beta zeolite for controlling the cold-start hydrocarbon emission from a gasoline vehicle

In this work, cold start experiments results showed that the HC catcher coated with 1% iron content is more effective than that with 3% iron content, the peak HC emission is reduced from 0.0029 g to 0.0018 g. To further reveal the reasons for the effects of BEA zeolite molecular sieves with different iron contents on HC adsorption, the measured HC emission components (butene, propene, ethene, acetaldehyde, and acetylene) were used as HC simulation molecules for molecular simulation experiments, the simulation results showed that, for single-component adsorption, the adsorption effect of beta zeolite molecular sieves with high iron content was better; for multi-component adsorption, acetaldehyde and butene maintained higher adsorption amounts, and the adsorption of acetaldehyde increased with the increase of the iron content in the beta zeolite molecular sieves; in the presence of water and CO2, the effect of water is greater than that of carbon dioxide, and its effect increases with the increase of iron content in beta zeolite molecular sieves. The maximum adsorption capacity of water can reach 4.5mmol/zeolite, which seriously affected the adsorption of HC molecules. Properly reducing the iron content of BEA zeolite molecular sieve is useful for enhancing its adsorption effect on the main HC simulated molecules.