Acetylene hydrogenation on Au-based catalysts
Acetylene hydrogenation on Au-based catalysts
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DOI：
10.1023/a:1022694505504
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发表时间：
2003-03-01
影响因子：
2.8
通讯作者：
Goodman, DW
中科院分区：
文献类型：
--
作者：
Choudhary, TV;Sivadinarayana, C;Goodman, DW
研究了Au/TiO2Pd/TiO2Au-Pd/TiO2型催化剂在高乙炔转化率下的乙炔加氢反应。Au/TiO2光催化剂(avg.Au-膦络合物在TiO2光催化剂上的程序升温还原氧化制得的催化剂在100%乙炔转化率下仍表现出很高的乙烯生成选择性。采用常规浸渍法制备了Au/TiO2光催化剂。粒径为30 nm)，乙炔加氢活性可忽略不计。虽然Au催化剂对乙烯具有较高的选择性，但乙炔转化活性和催化剂稳定性不如Pd基催化剂。氧化还原法制备的Au-Pd催化剂具有较高的乙炔转化率和乙烯选择性。有趣的是，用初湿法制备的Au-Pd催化剂对乙烯的选择性很差(与单金属Pd催化剂相当)。高分辨电子显微镜和X射线能谱研究表明，氧化还原法制备了双金属Au-Pd催化剂，而后者在载体上生成了单独的Pd和Au颗粒。
Hydrogenation of acetylene has been investigated on Au/TiO2, Pd/TiO2 and Au-Pd/TiO2 catalysts at high acetylene conversion levels. The Au/TiO2 catalyst (avg. particle size: 4.6 nm) synthesized by the temperature-programmed reduction oxidation of an Au-phosphine complex on TiO2 showed remarkably high selectivity to ethylene formation even at 100% acetylene conversion. Au/TiO2 prepared by the conventional incipient wet impregnation method (avg. particle size: 30 nm), on the other hand, showed negligible activity for acetylene hydrogenation. Although the Au catalysts showed high selectivity for ethylene, the acetylene conversion activity and catalyst stability were inferior to the Pd-based catalysts. Au Pd catalysts prepared by the redox method showed high acetylene conversions as well as high selectivity for ethylene. Interestingly Au-Pd catalysts prepared by depositing Pd via the incipient wetness method on Au/TiO2 showed very poor selectivity (comparable to mono-metallic Pd catalysts) for ethylene. High-resolution transmission electron microscopy (TEM) studies coupled with energy dispersive X-ray spectroscopy (EDS) showed that while the redox method produced bimetallic Au-Pd catalysts, the latter method produced individual Pd and Au particles on the support.