Coupled Palladium–Tungsten Bimetallic Nanosheets/TiO2 Hybrids with Enhanced Catalytic Activity and Stability for the Oxidative Removal of Benzene
Coupled Palladium–Tungsten Bimetallic Nanosheets/TiO2 Hybrids with Enhanced Catalytic Activity and Stability for the Oxidative Removal of Benzene
复制标题
耦合钯-钨双金属纳米片/TiO2 杂化物，具有增强的氧化去除苯的催化活性和稳定性
DOI：
10.1021/acs.est.9b00370
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发表时间：
2019
影响因子：
11.4
通讯作者：
Hongxing Dai
中科院分区：
文献类型：
--
作者：
Yijing Liang;Yuxi Liu;Jiguang Deng;Kunfeng Zhang;Zhiquan Hou;Xingtian Zhao;Xing Zhang;Kaiyue Zhang;Rujian Wei;Hongxing Dai
由于传统的Pd基催化剂经常受到水的严重失活，因此开发具有良好活性和耐湿性的催化剂对于有效控制挥发性有机化合物（VOC）的排放是重要的。在这里，我们报告了高效的合成钯-钨纳米片具有非常高的分散的钨物种。负载型催化剂（TiO 2/PdW）具有良好的苯氧化性能，在200 °C、40 000 mL g-1h-1空速下，苯的转化率可达90%。TiO 2/PdW催化剂的耐水性也优于传统的Pd/TiO 2催化剂。这种高催化效率的原因是在紧密接触的PdOx-WOx-TiO 2排列中，活性Pd 2 +/Pd 0电对容易进行氧化还原循环。我们认为TiO 2/PdW催化剂具有良好的耐水性的原因是其晶格氧可以有效地补充苯氧化所消耗的活性PdOx位中的氧。提出了催化剂促进苯转化的四步反应机理。本工作为高湿条件下VOCs的高效催化剂的合理设计提供了有益的思路。
Since the conventional Pd-based catalysts often suffer severe deactivation by water, development of a catalyst with good activity and moisture-resistance ability is of importance in effectively controlling emissions of volatile organic compounds (VOCs). Herein, we report the efficient synthesis of ultrathin palladium–tungsten bimetallic nanosheets with exceptionally high dispersion of tungsten species. The supported catalyst (TiO2/PdW) shows good performance for benzene oxidation, and 90% conversion is achieved at a temperature of 200 °C and a space velocity of 40 000 mL g–1h–1. The TiO2/PdW catalyst also exhibits better water-tolerant ability than the traditional Pd/TiO2catalyst. The high catalytic efficiency can be explained by the facile redox cycle of the active Pd2+/Pd0couple in the close-contact PdOx–WOx–TiO2arrangement. We propose that the reason for good tolerance to water is that the lattice oxygen of the TiO2/PdW catalyst can effectively replenish the oxygen in active PdOxsites consumed by benzene oxidation. A four-step benzene transformation mechanism promoted by the catalyst is proposed. The present work provides a useful idea for the rational design of efficient bimetallic catalysts for the removal of VOCs under the high humidity conditions.