PdO/CeO2类芬顿降解酸性橙7和水杨酸的催化性能

采用沉淀-沉积法制备了PdO/CeO2催化剂,并使用X射线衍射、高分辨透射电镜、N2吸附-脱附等温线、X射线光电子能谱和Raman光谱对催化剂进行了表征.表征结果显示, Pd在复合物中以Pd2+形式存在； PdO和CeO2间的相互作用提高了CeO2中的Ce3+含量.通过酸性橙7和水杨酸的类芬顿降解考察了PdO/CeO2的多相类芬顿和可见光芬顿催化活性.结果表明, PdO沉积显著地促进了水杨酸的类芬顿降解,催化剂的PdO含量为1.0 at%时其活性最佳.染料酸性橙7在可见光照射条件下会引发染料光敏化效应.吸附的染料分子在光激发后通过界面电子注入促进了Ce3+自表面过氧物种的再生.由此, PdO负载和可见光照射的共同作用下,1.0 PdO/CeO2催化剂的酸性橙7类芬顿降解速率常数为3.90 h-1,为纯CeO2活性的50倍左右.

The enhanced Fenton-like catalytic performance of PdO/CeO2 for the degradation of acid orange 7 and salicylic acid

A PdO/CeO2 catalyst was prepared by deposition‐precipitation method and characterized with X‐ray diffraction, high‐resolution transmission electron microscopy, N2 adsorption‐desorption, X‐ray photoelectron spectroscopy and Raman spectroscopy. The results show that the Pd is pre‐sented as Pd2+in the catalyst. The interaction between the deposited PdO and CeO2 increases the Ce3+content. The catalytic activity of PdO/CeO2 was tested in the heterogeneous Fenton‐like degra‐dation of acid orange 7 (AO7) and salicylic acid (SA), both in the dark and under visible irradiation. Deposition of PdO accelerates the Fenton‐like degradation of SA, which reaches a maximum at 1.0 atom%PdO loading. A dye sensitization effect was seen with AO7 under visible irradiation. Dye sensitization promotes the regeneration of Ce3+by interfacial peroxides species through interfacial electron injection. Consequently, the combined effects of PdO loading and visible light irradiating enhanced the Fenton‐like activity to a reaction rate constant of 3.90 h–1 for the 1.0 PdO/CeO2, a ca. 50‐fold improvement.