Catalytic Performance and Reaction Mechanisms of Ethyl Acetate Oxidation over the Au–Pd/TiO2 Catalysts
Catalytic Performance and Reaction Mechanisms of Ethyl Acetate Oxidation over the Au–Pd/TiO2 Catalysts
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DOI：
10.3390/catal13040643
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发表时间：
2023-03
期刊：
影响因子：
3.9
通讯作者：
Minming Bao;Yuxi Liu;Jiguang Deng;L. Jing;Zhiquan Hou;Zhiwei Wang;Lu Wei;Xiaohui Yu;H. Dai
中科院分区：
文献类型：
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作者：
Minming Bao;Yuxi Liu;Jiguang Deng;L. Jing;Zhiquan Hou;Zhiwei Wang;Lu Wei;Xiaohui Yu;H. Dai
开发高效、稳定的催化剂对消除挥发性有机污染物（VOCs）具有重要意义。在这项工作中，AuPdx纳米颗粒（NPs）通过静电吸附方法负载在TiO 2上以生成yAuPdx/TiO 2（即，0.35 AuPd0.46/TiO 2、0.34 AuPd2.09/TiO 2和0.37 AuPd2.72/TiO 2; x和y分别为Pd/Au摩尔比和AuPdx负载量; x = 0.46-2.72; y = 0.34-0.37 wt%）催化剂，并测定了它们对乙酸乙酯氧化的催化活性。结果表明，0.37AuPd2.72/TiO 2催化剂的活性最高（在SV = 40，000 mL/（g h），Ea = 37 kJ/mol，220 ℃下的比反应速率= 113.8 µmol/（gPd s）时，T50% = 217 ℃且T90% = 239 ℃，和翻转频率（TOF贵金属）在220 °C = 109.7 × 10−3 s−1）。0.37AuPd2.72/TiO 2样品的高催化性能归因于AuPd2.72纳米粒子的良好分散性、强的氧化还原能力、大的乙酸乙酯吸附容量以及AuPdx与TiO 2之间的强相互作用。乙醛、乙醇和乙酸是乙酸乙酯氧化的主要中间体，AuPdx纳米颗粒的负载有效地减少了有毒副产物乙醛的形成。乙酸乙酯在0.34AuPd2.09/TiO 2催化剂上的氧化反应可能是通过乙酸乙酯→乙醇→乙酸→乙酸→ CO2和H2O的反应途径进行的。我们相信，所获得的结果可能会提供一个有用的想法，在工业条件下的催化剂的设计和理解挥发性有机物的氧化机理。
The development of efficient and stable catalysts is of great importance for the elimination of volatile organic pollutants (VOCs). In this work, AuPdx nanoparticles (NPs) were loaded on TiO2 through the electrostatic adsorption approach to generate the yAuPdx/TiO2 (i.e., 0.35AuPd0.46/TiO2, 0.34AuPd2.09/TiO2, and 0.37AuPd2.72/TiO2; x and y are Pd/Au molar ratio and AuPdx loading, respectively; x = 0.46–2.72; and y = 0.34–0.37 wt%) catalysts, and their catalytic activities for the oxidation of ethyl acetate were determined. The results showed that the 0.37AuPd2.72/TiO2 sample exhibited the best activity (T50% = 217 °C and T90% = 239 °C at SV = 40,000 mL/(g h), Ea = 37 kJ/mol, specific reaction rate at 220 °C = 113.8 µmol/(gPd s), and turnover frequency (TOFNoble metal) at 220 °C = 109.7 × 10−3 s−1). The high catalytic performance of the 0.37AuPd2.72/TiO2 sample was attributed to the good dispersion of AuPd2.72 NPs, the strong redox ability, the large ethyl acetate adsorption capacity, and the strong interaction between AuPdx and TiO2. Acetaldehyde, ethanol, and acetic acid are the main intermediates in the oxidation of ethyl acetate, and the loading of AuPdx NPs effectively reduces the formation of the toxic by-product acetaldehyde. The oxidation of ethyl acetate over the 0.34AuPd2.09/TiO2 sample might occur via the pathway of ethyl acetate → ethanol → acetic acid → acetate → CO2 and H2O. We believe that the obtained results may provide a useful idea for the design of bimetallic catalysts under industrial conditions and for understanding the VOCs oxidation mechanisms.