Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
School of Civil & Environmental Engineering and Geography Science, Ningbo University, Ningbo 315211, China.
J Environ Sci (China). 2025 Feb;148:336-349. doi: 10.1016/j.jes.2023.05.011. Epub 2023 May 20.
Catalytic destruction is an ascendant technology for the abatement of volatile organic compounds (VOCs) originating from solvent-based industrial processes. The varied composition tends to influence each VOC's catalytic behavior in the reaction mixture. We investigated the catalytic destruction of multi-component VOCs including dichloromethane (DCM) and ethyl acetate (EA), as representatives from pharmaceutical waste gases, over co-supported HPO-RuO/CeO catalyst. A mutual inhibitory effect relating to concentrations because of competitive adsorption was verified in the binary VOCs oxidation and EA posed a more negative effect on DCM oxidation owing to EA's superior adsorption capacity. Preferential adsorption of EA on acidic sites (HPO/CeO) promoted DCM activation on basic sites (O) and the dominating EA oxidation blocked DCM's access to oxidation centers (RuO/CeO), resulting in boosted monochloromethane yield and increased chlorine deposition for DCM oxidation. The impaired redox ability of Ru species owing to chlorine deposition in turn jeopardized deep oxidation of EA and its by-products, leading to increased gaseous by-products such as acetic acid originating from EA pyrolysis. Notably, DCM at low concentration slightly promoted EA conversion at low temperatures with or without water, consistent with the enhanced EA adsorption in co-adsorption analyses. This was mainly due to that DCM impeded the shielding effect of hydrolysate deposition from rapid EA hydrolysis depending on the decreased acidity. Moreover, water benefited EA hydrolysis but decreased CO selectivity while the generated water derived from EA was likely to affect DCM transformation. This work may provide theoretical guidance for the promotion of applied catalysts toward industrial applications.
催化破坏是一种用于去除溶剂型工业过程中产生的挥发性有机化合物 (VOCs) 的新兴技术。不同的成分往往会影响每种 VOC 在反应混合物中的催化行为。我们研究了多组分 VOC 的催化破坏，包括二氯甲烷 (DCM) 和乙酸乙酯 (EA)，它们分别代表来自制药废气的 VOC。在二元 VOCs 氧化中验证了由于竞争吸附导致浓度相关的相互抑制效应，并且由于 EA 的吸附能力更强，EA 对 DCM 氧化的影响更为负面。EA 在酸性位（HPO/CeO）上的优先吸附促进了 DCM 在碱性位（O）上的活化，并且 EA 氧化的主导作用阻止了 DCM 进入氧化中心（RuO/CeO），导致 DCM 氧化的一氯甲烷产率增加和氯沉积增加。氯沉积对 Ru 物种的还原能力的损害反过来又危及 EA 及其副产物的深度氧化，导致来自 EA 热解的气态副产物（如乙酸）增加。值得注意的是，在低温下，即使有水存在，低浓度的 DCM 也会略微促进 EA 的转化，这与共吸附分析中增强的 EA 吸附一致。这主要是由于 DCM 阻碍了水解产物沉积的屏蔽效应，从而导致 EA 的水解加快，酸度降低。此外，水有利于 EA 水解，但降低了 CO 选择性，而来自 EA 的生成水可能会影响 DCM 的转化。这项工作可能为促进工业应用中的应用催化剂提供理论指导。
