Alloying of gold with palladium: An effective strategy to improve catalytic stability and chlorine-tolerance of the 3DOM CeO2 -supported catalysts in trichloroethylene combustion
Alloying of gold with palladium: An effective strategy to improve catalytic stability and chlorine-tolerance of the 3DOM CeO2 -supported catalysts in trichloroethylene combustion
复制标题
金与钯合金化：提高 3DOM CeO2 负载催化剂在三氯乙烯燃烧中的催化稳定性和耐氯性的有效策略
DOI：
10.1016/j.apcatb.2019.117879
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Dai Hongxing
中科院分区：
文献类型：
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作者：
Zhang Xing;Liu Yuxi;Deng Jiguang;Yu Xiaohui;Han Zhuo;Zhang Kunfeng;Dai Hongxing
以聚甲基丙烯酸甲酯为模板，聚乙烯醇保护还原法制备了三维有序大孔CeO2负载的Au-Pd合金(xAuPdy/3DOM CeO2，x为Au和Pd的总负载量(wt%)，Pd/Au的摩尔比)。采用多种分析技术对样品进行了表征，并对其催化三氯乙烯燃烧性能进行了评价。结果表明，3DOM-CeO2/3DOM-AuPdy具有良好的3DOM结构，贵金属纳米颗粒(NPs)均匀分散在3DOM-CeO2的骨架表面，尺寸为3-4 nm。在所有样品中，2.85AuPd1.87/3DOM CeO2的催化活性最高，在空速为20,000 mL/(Gh)、三氯乙烯转化率为90%(T90%)时的温度为415 °C。此外，2.85AuPd1.87/3DOM CeO2样品具有最低的表观活化能(33MOLkJ/ )、良好的催化稳定性和良好的耐湿性和耐氯性。Au与Pd的合金化改变了TCE的氧化途径，减少了全氯乙烯的生成。结果表明，2.85AuPd1.87/3DOM CeO2对TCE燃烧具有良好的催化性能，这与AuPd1.87合金纳米粒子的高度分散性、高吸附氧物种浓度、良好的低温还原性能、AuPd1.87NPs与3DOM CeO2之间的强相互作用以及高质量的3DOM结构和高表面酸性有关。
The three-dimensionally ordered macroporous (3DOM) CeO2-supported Au–Pd alloys (xAuPdy/3DOM CeO2,xis the total loading (wt%) of Au and Pd, andyis the Pd/Au molar ratio) were synthesized using the polymethyl methacrylate-templating and polyvinyl alcohol-protected reduction methods. The samples were characterized by a number of analytical techniques, and their catalytic performance was evaluated for the combustion of trichloroethylene (TCE). It is found that thexAuPdy/3DOM CeO2samples displayed a good-quality 3DOM architecture, and the noble metal nanoparticles (NPs) with a size of 3–4 nm were uniformly dispersed on the skeleton surface of 3DOM CeO2. Among all of the samples, 2.85AuPd1.87/3DOM CeO2exhibited the highest catalytic activity, with the temperature at a TCE conversion of 90% (T90%) being 415 °C at a space velocity of 20,000 mL/(g h). Furthermore, the 2.85AuPd1.87/3DOM CeO2sample possessed the lowest apparent activation energy (33 kJ/mol), excellent catalytic stability, and good moisture- and chlorine-tolerant behaviors. Alloying of Au with Pd changed the pathway of TCE oxidation and reduced formation of perchloroethylene. We conclude that the excellent catalytic performance for TCE combustion of 2.85AuPd1.87/3DOM CeO2was associated with the highly dispersed AuPd1.87alloy NPs, high adsorbed oxygen species concentration, good low-temperature reducibility, and strong interaction between AuPd1.87NPs and 3DOM CeO2as well as the high-quality 3DOM structure and high surface acidity.