Bo Li,Dachao Yuan,Luping Ma,Chengcheng Shi,Yaguang Li
Catalytic combustion of chlorinated volatile organic compounds (CVOCs) driven by natural sunlight is the promising CVOCs elimination method, which has not been realized. In this work, we designed a new sunlight-driven catalytic system for CVOCs combustion based on a scalable CuMnCeO x gel and a new photothermal conversion device. The CVOCs elimination rate of CuMnCeO x gel was reached to 99% at 250 °C, 25 times higher than that of CuMnCeO x in bulk form. Further, the new photothermal conversion device could heat the CuMnCeO x gel to 300 °C under one standard solar irradiation and this joint showed a stable one standard sunlight-driven CVOCs combustion at the rate of 6.8 mmol g −1 h −1 , which was more than 7.8 times higher than the state of the art of photocatalytic CVOCs decomposition. Moreover, the new sunlight-driven thermal catalytic system was able to stable full oxidize the CVOCs in the concentration from 0.1 to 1000 ppm. Therefore, the natural sunlight-driven thermal CVOCs combustion system with high activity and zero secondary pollution shows the potential for large-scale industrial applications.
Fangda Wei,Haiyan Bai,Xi Cui,Feng Wu,Zhixiong You,Lin Yue,Jinjun Li
Oxygenated and chlorinated volatile organic compounds (OVOCs/CVOCs), which are widely emitted from fuel storage and solvent applications, require effective adsorption and recovery strategies to enhance resource utilization efficiency. In this study, Fe-modified activated carbons (ACs) were prepared via two distinct methods: adsorption and impregnation. Adsorption-based modification of AC facilitated equilibrium-driven Fe 3 + complexation on functional groups, resulting in atomically dispersed Fe. In contrast, the impregnation method induced rapid hydrolysis of Fe species during solvent evaporation, which promoted localized Fe accumulation. The adsorption performances and mechanisms toward representative OVOCs and CVOCs were investigated. Results demonstrated that 0.6 %Fe(A)/AC prepared through the adsorption method exhibited enhanced adsorption capacities for methanol and dichloromethane by 48 % and 28 %, respectively, under dry conditions compared to pristine AC. Remarkably, 0.6 %Fe(A)/AC maintained superior adsorption performance at 60 % relative humidity compared to other samples. The atomic-level dispersion of Fe atoms facilitated the high dispersion of coordinated hydroxyl groups, which inhibited collective hydrogen bonding with H 2 O molecules and mitigated the rapid formation of water clusters. Conversely, Fe species agglomeration in 5.5 %Fe(I)/AC prepared through the impregnation method caused significant performance deterioration at 60 % relative humidity. Theoretical calculations demonstrated that Fe atoms deposited on AC exhibited high adsorption energies for both OVOCs and CVOCs. Moreover, hydrolysis-derived hydroxyl groups bound to Fe functioned as supplementary active sites, further enhancing adsorption capacity. This work provides theoretical and technical insights for designing efficient OVOC and CVOC adsorbents.
Enhancing the surface acidity has been seen as an effective strategy to optimize the performance of catalysts for the degradation of chlorinated volatile organic compounds (CVOCs). Herein, a series of catalysts are constructed by introducing Lewis and Brønsted acid sites into the skeleton surface of three-dimensional ordered macroporous (3DOM) CeO2. By a systematic study, we find that the introduction of Lewis acid sites can enhance the redox capacity of CeO2, while the surface Brønsted acid sites of the material promote chlorobenzene (CB) degradation through hydrolysis that is an effective degradation route to generate less chlorinated organic by-products. The optimal S–Ce0.7Zr0.3O2 with both abundant surface Lewis and Brønsted acid sites presents a stable activity and only 1.2% Cl2 selectivity with ∼90% CB conversion at 410 °C for 24 h. This work reveals the different roles and synergistic effects of Lewis and Brønsted acid sites to develop environmentally friendly CVOC combustion catalysts.
危险品化学品经营许可证（带存储）