| The removal of the volatile organic compounds is a hot topic in the environmental protection. In situ adsorption-catalytic method combines the advantages that low concentration VOCs can be concentrated by adsorption and activated at low temperature by catalytic combustion. It has the advantages of reducing the amount of organic gas and decreasing the energy consumption, with no generation of secondary pollution at moderate temperatures. Thus, in situ adsorption-catalytic catalytic has been recognized as one of the promising techniques for VOCs abatement. The key of this method is the choice of adsorbent and catalyst, much attention should be paid to the improvement of adsorbent with good adsorption and regeneration as well as catalyst with high activity at low temperatures for the economic and practical significance. The main contents of this paper are as follows:1. Four different types of adsorbents, SBA-15, MCM-41, NaY and SiO2, were used to study the dynamic adsorption/desorption of toluene. In order to further investigate the influence of pore structure on its adsorption performance, two SBA-15 samples with different microspores were also selected. Results showed that the toluene adsorption capacity of the samples followed the following trend:NaY＞SBA-15-2＞SBA-15-1＞MCM-41＞SiO2. Since the complete desorption temperature of NaY for toluene is high (> 350℃), which is not conductive to the recycling of materials. While the complete desorption temperature of toluene on mesoporous and amorphous materials was much lower (< 150℃). It was suggested that SBA-15 sample consisting of longer 1D mesopore channels connected by complementary micropores was an ideal adsorption material. Besides, the synergitic effect existed between mesopores and micropores for toluene adsorption. The mesopores were in favor of toluene diffusion, micropores were benefit for the melocular adsorption, and the more micropores, the better adsorption properties.2. Ag/SBA-15 catalysts were prepared by incipient wetness impregnation method to investigate the influence of different silver contents and pretreatment condition for their adsorption and catalytic performance. It was shown that 12 wt%Ag/SBA-15 showed a better low-temperature catalytic activity with ignition temperature at 163℃. Pretreatment atmosphere greatly influenced the state of silver species, and therefore the silver catalyst with well dispersed Ag nanoparticles after hydrogen reduction following O2 pretreatment exhibited the best performance for toluene oxidation. The further research on dynamic adsorption and temperature programmed desorption (TPD) of toluene showed that competitive adsorption appeared between gas oxygen and toluene during the co-adsorption process over the catalysts. Oxygen easily occupied the stronger adsorption centers or decreased the affinity of toluene with silver surface sites, resulted in the decrease of desorption temperature for toluene from the catalysts surface. The subsurface oxygen presence in the catalyst enhanced the the affinity of metal with toluene, making the desorption temperature move to higher region.3. In order to reduce the cost of the catalyst application, parts of silver can be substitured by transition metal (Cu, Co, Ce and Mn) in the silver-based catalyst. The results indicated that the two component catalyst showed the the best catalytic activity when copper and silver ratio was 1:1. It was found that that the presence of silver resulted in the more dispersion of copper oxides nanoparticles. The synergitic effect between silver and copper oxides accelerated the charge transferation between copper and silver species, which also reduced the activation energy of toluene in comparison with the single component catalysts, thereby enhancing the catalytic activity of toluene.
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