School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, China; Zhejiang Province Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou, 310012, China.
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, China.
J Environ Manage. 2024 Jun;362:121334. doi: 10.1016/j.jenvman.2024.121334. Epub 2024 Jun 1.
A series of V-xCe/Ti catalysts was prepared by a step impregnation method with gradual increased Ce amount. Compared to the commercial V-W/Ti catalysts, the V-xCe/Ti catalysts exhibited considerably higher CO selectivity during the oxidation of naphthalene (Nap), and less intermediates or by-products were detected both in gas phase and on the surface of the catalysts. Through a series of characterizations, it was found that abundance of weak basic sites in the form of OH was introduced by Ce, as well as the oxygen vacancies caused by the redox cycle of V+Ce↔V+Ce. The weak basic sites introduced by Ce could greatly enhance the Nap adsorption, and the Nap adsorbed was quickly converted to naphthol on Ce-OH. Furthermore, V existed at a high valence with the interaction of V and Ce, and the oxygen vacancies also increased the O and O. It improved the redox ability and the regeneration of Ce-OH on V-xCe/Ti catalysts. The intermediates could be further oxidized, and the Ce-OH consumed in the reaction could recover quickly. Therefore, almost 100% Nap conversion and a high CO selectivity was observed in the V-xCe/Ti catalysts system.
采用逐步增加铈量的分步浸渍法制备了一系列 V-xCe/Ti 催化剂。与商业 V-W/Ti 催化剂相比，V-xCe/Ti 催化剂在萘（Nap）氧化过程中表现出相当高的 CO 选择性，并且在气相和催化剂表面都检测到较少的中间体或副产物。通过一系列表征发现，Ce 引入了大量以 OH 形式存在的弱碱性位，以及由 V+Ce↔V+Ce 氧化还原循环引起的氧空位。Ce 引入的弱碱性位可以大大增强 Nap 的吸附，并且 Nap 吸附物在 Ce-OH 上迅速转化为萘酚。此外，V 以高价存在并与 V 和 Ce 相互作用，氧空位也增加了 O 和 O。这提高了 V-xCe/Ti 催化剂上的氧化还原能力和 Ce-OH 的再生能力。中间产物可以进一步氧化，反应中消耗的 Ce-OH 可以快速恢复。因此，在 V-xCe/Ti 催化剂体系中观察到几乎 100%的 Nap 转化率和高 CO 选择性。
