Ozone decomposition into free radicals, which can be facilitated by enhancing electron transfer between ozone and catalyst, is an important segment in catalytic ozonation. We doped cerium uniformly on γ-Al₂O₃ with an impregnation–calcination method to enhance electron transfer in catalytic ozonation of phenol in aqueous solution. The removal efficiency of phenol is raised from 39.7% by ozonation alone to 46.3% by catalytic ozonation with Ce/Al₂O₃ in 50 min reaction. A higher Ce³⁺/Ce⁴⁺ ratio in Ce/Al₂O₃ witnesses a higher electron transfer rate in catalytic ozonation and thus a higher degradation efficiency of phenol, illustrating that the activity of Ce/Al₂O₃ depends on the valence state of Ce. The electron transfer cycle is formed by the electron donation from Ce³⁺ to ozone molecule and the electron acceptance of Ce⁴⁺ from adjacent lattice oxygen. After getting the electron, the ozone molecule is decomposed to generate free radical of ·OH on the surface of Ce/Al₂O₃. The continuous flow experiments exhibit a stable and high catalytic activity of Ce/Al₂O₃ for catalytic ozonation, implying the feasibility in practical application.

臭氧分解成自由基可以通过增强臭氧与催化剂之间的电子转移来促进，这是催化臭氧化的重要环节。我们均匀掺杂铈上的γ-Al ₂ ö ₃具有浸渍煅烧的方法增强在水溶液中的苯酚催化臭氧化的电子转移。在50分钟的反应中，通过用Ce / Al ₂ O ₃催化臭氧氧化，苯酚的去除效率从仅进行臭氧氧化的39.7％提高到46.3％。Ce / Al ₂ O _3中较高的Ce ³⁺ / Ce ⁴⁺比可见，在催化臭氧化中电子转移速率较高，因此苯酚的降解效率较高，这说明Ce / Al ₂ O ₃的活性取决于Ce的价态。电子转移循环是由Ce ³⁺向臭氧分子的电子给体和相邻晶格氧对Ce ⁴⁺的电子接受所形成的。获得电子后，臭氧分子分解，在Ce / Al ₂ O ₃表面上生成·OH自由基。连续流动实验表明Ce / Al ₂ O ₃具有稳定和高的催化臭氧氧化活性，这表明其在实际应用中的可行性。