Vacuum ultraviolet (VUV)-based photocatalytic oxidation for toluene degradation over pure CeO2
Vacuum ultraviolet (VUV)-based photocatalytic oxidation for toluene degradation over pure CeO2
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DOI：
10.1016/j.ces.2019.01.056
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发表时间：
2019-06
影响因子：
4.7
通讯作者：
Muyan Wu;Yingguang Zhang;W. Szeto;W. Pan;Haibao Huang;D. Leung
中科院分区：
文献类型：
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作者：
Muyan Wu;Yingguang Zhang;W. Szeto;W. Pan;Haibao Huang;D. Leung
挥发性有机化合物（VOCs）是环境中最受关注的污染物之一，其治理已引起了大量的研究。真空紫外光催化氧化技术是一种很有前途的VOCs治理技术。CeO 2是一种很有前途的VUV-PCO催化剂，在臭氧氧化和臭氧氧化过程中均具有催化能力。本研究合成了三种典型的具有不同纳米结构的纯CeO 2，并创造性地将其应用于甲苯的VUV光催化氧化。采用BET、SEM、TEM、XRD、拉曼、XPS、H2-TPR和DRS等测试手段对不同CeO 2样品进行了表征。结果表明，合成的CeO 2样品对甲苯的降解效果比商业样品有更显著的提高。更高的考克斯生成和矿化率得到与使用所有的合成CeO 2样品。与市售CeO 2相比，合成样品具有更好的臭氧去除能力，CeO 2纳米棒催化剂的臭氧分解活性最好。所有CeO 2催化剂都存在着催化氧化和催化臭氧化的双重作用。Ce 3+的加入量对甲苯的氧化和臭氧化都有重要影响，Ce 3+的加入量越大，甲苯的去除效果越好。不同CeO 2样品在紫外光照射下表现出不同的电化学行为，进一步解释了光催化活性的差异。
Volatile organic compounds (VOCs) are one of the biggest concerns in the ambient environment that have attracted a great number of studies related to its remediation. Vacuum ultraviolet (VUV)-based photocatalytic oxidation (PCO) is a promising technology in controlling VOCs. CeO2is found to be a promising catalyst for the VUV-PCO technology possessing catalytic capacities in both the photocatalysis and ozonation processes. In this study, three typical kinds of pure CeO2with various nanostructures were synthesized and creatively applied for VUV-photocatalytic oxidation of toluene. Material characterizations, including BET, SEM, TEM, XRD, Raman, XPS, H2-TPR and DRS, were conducted to characterize different CeO2samples. Results indicated that synthetic CeO2samples have a much more remarkable enhancement in degrading toluene compared to commercial ones. Higher COx generation and mineralization rates were obtained with the use of all the synthetic CeO2samples. Compared to commercial CeO2, the synthetic samples have much better capacity towards removing ozone and the best activity in ozone decomposition was observed in CeO2Nanorods catalysts. Both the effects of photocatalysis and catalytic ozonation exist in all the CeO2catalysts. The amount of Ce3+plays a critical role in both the catalytic activity of photocatalysis and ozonation that higher ratio of Ce3+leads to better performance in toluene removal. The differences in photocatalytic activity were further explained by the results of electrochemical behaviors of different CeO2samples which showed varying responses to UV irradiation.