Performance and poisoning analysis of organic sulfur resistance of Pd-Ce catalyst in catalytic oxidation of VOCs

Abstract

In this paper, the effect of organic sulfur on the catalytic oxidation of toluene was explored. It was found that the low concentration of organic sulfur could cause rapid deactivation of the catalyst, and the activity of the catalyst could be restored to 100% after stopping the application of sulfur. The sulfation modification could significantly improve the organic sulfur resistance of the catalyst by changing the support and the sulfation modification of the support. There was a large amount of carbon deposition and a small amount of S-containing substances on the catalyst surface after the introduction of organic sulfur through the methods of TG, BET, FTIR, SEM (Mapping) and XPS. Then, through in-situ DRIFT and CH3SH-TPD, it was found that sulfation modification could inhibit the adsorption of organic sulfur on the catalyst surface and reduce the competitive adsorption. The decrease of catalyst efficiency due to the presence of organic sulfur in the reaction gas during VOCs catalytic oxidation is mainly due to the competitive adsorption of organic sulfur and VOCs molecules, and the temperature of VOCs catalytic oxidation of organic sulfur. Some polyhydrocarbons, ethyl sulfide, dimethyl sulfoxide and other substances were produced by incomplete oxidation, which covered the surface of the catalyst due to adsorption or deposition, resulting in catalyst poisoning.