Shao Shengjuan, Cheng Ting, Cheng Yifan, Chen Bingxin
Department of Chemistry and Chemical Engineering, Taiyuan Institute of Technology Taiyuan 030008 China
School of Chemistry and Chemical Engineering, North University of China Taiyuan Shanxi 030051 China.
RSC Adv. 2024 Sep 30;14(42):30990-31002. doi: 10.1039/d4ra06148a. eCollection 2024 Sep 24.
Ce-Mn binary oxides supported on AlO (Ce-Mn/AlO), with enhanced activity and stability for catalytic ozonation of benzoic acid, were synthesized using a facile impregnation method. The competitive synergetic effects between cerium and manganese significantly influenced the structural characteristics and catalytic performance of the catalysts depending on the impregnation sequence. Catalysts prepared the one-step impregnation process exhibited a higher concentration of homogeneous Ce species on the catalyst surface. This led to an increase in surface oxygen vacancies, thereby enhancing catalytic activity. In contrast, the two-step impregnation process resulted in fewer oxygen vacancies due to reduced competitive effects between cerium and manganese. Overall, the optimized Ce-Mn/AlO catalysts demonstrated improved catalytic performance in ozonation reactions, highlighting the importance of impregnation method and calcination conditions in tailoring catalyst properties for enhanced activity and stability. Oxygen vacancies play a crucial role as active sites for ozone adsorption and dissociation into *O and *O, facilitated by the reduction of Mn to Mn and the oxidation of Ce to Ce. This process forms an electron closed loop that maintains electron balance. The synergistic interactions between cerium and manganese enable rapid electron transfer between Ce and Mn, facilitating the regeneration of Ce and Mn. Due to the increase of the dual redox conjugate pairs and the surface reactive oxygen species, the catalytic ozonation activity and stability of Ce-Mn/AlO was enhanced.
采用简便的浸渍法合成了负载在AlO上的Ce-Mn二元氧化物（Ce-Mn/AlO），其对苯甲酸催化臭氧化具有增强的活性和稳定性。铈和锰之间的竞争协同效应根据浸渍顺序显著影响了催化剂的结构特征和催化性能。通过一步浸渍法制备的催化剂在催化剂表面表现出较高浓度的均匀Ce物种。这导致表面氧空位增加，从而提高了催化活性。相比之下，两步浸渍法由于铈和锰之间的竞争效应降低，导致氧空位减少。总体而言，优化后的Ce-Mn/AlO催化剂在臭氧化反应中表现出改善的催化性能，突出了浸渍方法和煅烧条件在调整催化剂性能以提高活性和稳定性方面的重要性。氧空位作为臭氧吸附和解离为O和O的活性位点起着关键作用，这是通过将Mn还原为Mn以及将Ce氧化为Ce来实现的。这个过程形成了一个保持电子平衡的电子闭环。铈和锰之间的协同相互作用使得Ce和Mn之间能够快速进行电子转移，促进了Ce和Mn的再生。由于双氧化还原共轭对和表面活性氧物种的增加，Ce-Mn/AlO的催化臭氧化活性和稳定性得到了增强。
