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Although free hydroxyl radical (·OH) generated on OMS-2-based catalysts during the catalytic ozonation process have been shown as important reactive oxygen species (ROSs) for toluene degradation, improvement of surface ·OH formation ability remains challenging. Here, Na, K, Rb, and Cs-OMS-2-SO 4 2-/ZSM-5 catalysts were prepared, characterized and evaluated for catalytic ozonation of toluene. Both characterizations and DFT calculations showed that the appropriate alkali metal introduction made the catalyst possess with appropriate crystalline, reducibility, and acidity, which was favorable for catalytic ozonation of toluene. Characterizations also showed that alkali metal introduction resulted in water molecule adsorption on Brönsted acid sites of the catalysts, which made water molecule activation by ozone to form ·OH more easily. The introduction of K+ content of ∼ 5.9 wt% yielded K-OMS-2-SO 4 2-/ZSM-5 catalyst with the highest Brönsted acid sites and thus formed the most ·OH among the five prepared catalysts. As a result, the catalyst exhibited excellent toluene conversion and CO x selectivity for catalytic ozonation of toluene at room temperature and ambient humidity. Furthermore, the catalytic activity of deactivated K-OMS-2-SO 4 2-/ZSM-5 catalyst was recovered after regeneration by a combination of water washing and heat treatment. Finally, a complete mechanism for toluene catalytic ozonation, catalyst deactivation, and regeneration was proposed. [Display omitted] • The alkali metal introduction promoted ·OH formation in OMS-2-SO 4 2-/ZSM-5 catalyst. • The increased ·OH facilitated toluene conversion over OMS-2-SO 4 2-/ZSM-5 catalyst. • A complete mechanism for toluene catalytic ozonation and deactivation was proposed. • A strategy for efficient regeneration of K-OMS-2-SO 4 2-/Z catalyst was developed. [ABSTRACT FROM AUTHOR]

A series of MnFe catalysts were prepared by hydrothermal synthesis combined with heat treatment at different temperatures. The characterizations demonstrated that MnFe-120 with both surface -OH and -NO 3 , MnFe-175 with surface -OH, MnFe-300 containing neither surface -OH nor -NO 3 , and MnFe-300-NO 3 containing surface -NO 3 were gained by drying or calcination and impregnation. The activity evaluation showed that the order of catalytic activity was MnFe-120 > MnFe-175 > MnFe-300-NO 3 > MnFe-300. Further, characterizations and experiment results revealed that O 3 adsorbed on the surface of the catalyst can interact with surface -OH and generated hydroxyl radicals (·OH). The presence of surface -NO 3 provided more Lewis acid sites, thereby promoting H 2 O adsorption and conversion to the surface -OH, which supplemented the surface -OH consumed by the interaction with O 3. It was deduced that the coexistence of surface -OH and -NO 3 improved the production of·OH, which synergistically promoted the catalytic ozonation of toluene. [Display omitted] • A series of MnFe catalysts with different amounts of surface -OH and -NO 3 were prepared. • MnFe catalyst containing both surface -OH and -NO 3 had a optimal catalytic ozonation performance for toluene. • O 3 adsorbed on the surface -OH sites and hydroxyl radicals (·OH) to oxidize toluene was produced. • H 2 O adsorbed on the surface -NO 3 sites and was converted to the surface -OH, which supplemented the surface -OH consumed. • The synergistic effect of surface -OH and -NO 3 increased the amount of·OH production. [ABSTRACT FROM AUTHOR]

Adsorptive removal of gas phase low concentration macromolecular organic component, represented by naphthalene, from the enclosed space using ordered mesoporous carbon (OMC) has been studied by molecular simulation and experimental investigation. The simulation results indicated that both adsorption capacity and adsorption stability of the OMCs for naphthalene decreased with the increase of pore sizes from 2 nm to 8 nm. Characterizations showed that the prepared OMCs had the pore structure similar to the simulated OMCs except for the rough surface. In particular, the adsorption performance of the prepared OMCs was significantly lower than that of the simulated OMCs when pore size was 2 nm and 3 nm, which was attributed to the rough inner surface of these adsorbents, blocking the narrow pore channels and significantly reducing the pore volume. OMC with pore size of 4 nm had the highest adsorption amount for naphthalene. The co-adsorption experiments in the presence of both naphthalene and toluene, acetone or water showed the adsorption performance of OMCs for naphthalene were almost unaffected by the presence of low concentration toluene and acetone, as well as high relative humidity. [Display omitted] • Adsorption of naphthalene by OMCs were investigated by simulation and experiment. • Realistic molecular models for OMCs were constructed by "delete atom" method. • The impact of pore structure on the adsorption of naphthalene was revealed. • OMC with pore size of 4 nm has the highest adsorption capacity for naphthalene. • OMCs show excellent adsorption selectivity and good moisture resistance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Adsorption of toluene and naphthalene by OMS were investigated by simulation. • The adsorption selectivity of toluene and naphthalene was predicted by IAST. • The mechanism of selective adsorption was elucidated at molecular level. • Adsorbents with the desired pore size were prepared by template synthesis method. • The experimental results are in good agreement with the simulation results. In order to ensure regeneration property of adsorption materials in the air pollution purification system of the airtight cabin, such as submarine and space station, it is necessary to selectively separate semi-volatile organic compounds whose desorption is difficult. For this reason, the effects of pore size on the adsorption capacity and adsorption selectivity of toluene and naphthalene were investigated by both molecular simulation and experimental investigation. The ordered porous silica-based adsorbents with pore sizes ranging from 1.0 nm to 2.8 nm were constructed by simulation and were prepared by template synthesis method in this study. Both simulation and experiment show that the adsorption capacity of toluene and naphthalene firstly increased and then decreased with the increase of the pore size of adsorbents from 1.0 nm to 2.8 nm, and the pore diameter (1.3 nm) corresponding to the maximum adsorption amount of toluene was smaller than that (2.3 nm) of naphthalene. Simulation results show that the adsorption energy and adsorption stability of naphthalene are higher than those of toluene, and binary-component co-adsorption experiments also testified that toluene molecules could be replaced by naphthalene molecules. The optimum pore size for selective adsorption of naphthalene is 2.3 nm. [ABSTRACT FROM AUTHOR]