The Performance Of Zeolite-supported Catalytic Materials For Toluene Abatement

Air pollution can seriously harm to the health of human.VOCs have been proved as important precursors for many pollutants like PM2.5.Therefore,it is particularly necessary to control and decrease VOCs emission.Catalytic combustion is considered as an efficient and environment-friendly technology and attracted much attention.The design and preparation of catalysts are the key factors.Noble metal and non-noble metals are two common types of catalysts,but the former is poor economical efficiency and limited for large-scale applications.The latter is inexpensive but poor activity and lack of hydrothermal stability.In this work,zeolite is choosed as the promising support.We succeedfully improve the performance of Pd-supported catalyst and MnOx-supported catalyst on toluene abatement by controlling the framework composition and cation of the zeolite support,respectively.Fe-ZSM-5 supported catalyst shows better performance in toluene combustion,compareing with the Al-ZSM-5 supported Pd catalyst.The influence of Pd concentration,low temperature reducibility,concentration of adsorbed oxygen and Pd species was investigated.The excellent performance of Pd/Fe-ZSM-5 was contributed to high concentration of the adsorbed oxygen spcies and better Pd0 stability.Water vapor barrier tests and life test results show that the catalyst has good resistance to long-life operation and potentialH-form and K-form Al-rich Beta-supported MnOx catalysts(MnOx/H-Beta-SDS and MnOx/K-Beta-SDS)as well as cation-free Beta supported MnOx catalysts(MnOx/Si-Beta)were successfully prepared.Their catalytic activities for toluene catalytic combustion show that the performance of zeolite-based catalysts is obviously better than that of MnOx/Al2O3,and the activity of MnOx/H-Beta-SDS catalyst shows the best activity.The factors of low temperature reducibility,adsorbed oxygen concentration and lattice oxygen concentration were investigated.The performance of MnOx/H-Beta-SDS may be attributed to the higher concentration of adsorbed oxygen.