Cold Plasma for Synthesizing High Performance Bimetallic PdCu catalysts: Effect of Reduction Sequence and Pd/Cu Atomic Ratios
Cold Plasma for Synthesizing High Performance Bimetallic PdCu catalysts: Effect of Reduction Sequence and Pd/Cu Atomic Ratios
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冷等离子体合成高性能双金属 PdCu 催化剂：还原顺序和 Pd/Cu 原子比的影响
DOI：
10.1007/s11244-017-0757-5
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发表时间：
2017-08-01
影响因子：
3.6
通讯作者：
Zhang, X. L.
中科院分区：
文献类型：
--
作者：
Di, L. B.;Duan, D. Z.;Zhang, X. L.
以Pd(NO3)2和Cu(NO3)2分别作为Pd和Cu的前驱体，采用简单的初始湿浸渍法和常压冷等离子体还原法制备了氧化铝负载双金属PdCu催化剂。考察了还原顺序和Pd/Cu原子比对催化剂结构和性能的影响。Pd和Cu前驱体共浸渍还原制备的PdCu/ Al2O3-P催化剂（Pd /Cu原子比为1:1）的CO氧化活性最高。同时，冷等离子体法制备的PdCu/ Al2O3-P催化剂的性能明显高于传统热还原法制备的催化剂。从合金的合金化程度、晶粒尺寸和分散性以及载体表面的化学吸附氧等方面考察了最佳结果。在PdCu/ Al2O3-P中，由于钯和铜的相互作用，获得了高合金化度、小尺寸和高分散性的PdCu纳米颗粒。此外，由于快速（6 min还原）和低温还原过程，PdCu/ Al2O3-P表面形成了更多的活性化学吸附氧。红外漫反射傅里叶变换和催化稳定性结果表明，Pd与碳种之间的相互作用减弱，有利于O2的吸附和活化。这使得PdCu/ Al2O3-P成为CO氧化的优良催化剂。常压冷等离子体是制备高性能双金属PdCu催化剂的一种简便有效的方法，在制备其他双金属催化剂方面具有潜在的应用前景。
Alumina supported bimetallic PdCu catalysts were prepared by simple incipient wetness impregnation followed by the process of atmospheric-pressure cold plasma reduction using Pd(NO3)2and Cu(NO3)2as Pd and Cu precursors, respectively. The influence of reduction sequence and Pd/Cu atomic ratios on the structure and performance of the catalysts were investigated. The highest CO oxidation activity was obtained for the PdCu catalyst (PdCu/Al2O3–P) prepared by co-impregnation and reduction of the Pd and Cu precursors with a Pd/Cu atomic ratio of 1:1. Meantime, the PdCu/Al2O3–P catalyst prepared by cold plasma exhibits much higher performance than that prepared by conventional thermal reduction. The optimum results from the alloying degree, crystallite size and dispersion of PdCu nanoparticles, and the chemisorbed oxygen species on the surface of the support. As a result of the interaction between Pd and Cu species, high alloying degree, small size and high dispersion of PdCu nanoparticles in PdCu/Al2O3–P were obtained. In addition, due to the fast (6 min reduction) and low temperature reduction process, more active chemisorbed oxygen species were formed on the surface of PdCu/Al2O3–P. The results of diffuse reflectance fourier transform infrared and catalytic stability show that the interaction between Pd and carbon species is weakened, which may facilitate the adsorption and activation of O2. These make PdCu/Al2O3–P an excellent catalyst for CO oxidation. Atmospheric-pressure cold plasma is proved to be a facile and efficient method for fabricating high performance bimetallic PdCu catalysts, which may have potential applications for preparing other bimetallic catalysts.