Kinetics and particle size effects in ethene hydrogenation over supported palladium catalysts at atmospheric pressure
Kinetics and particle size effects in ethene hydrogenation over supported palladium catalysts at atmospheric pressure
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DOI：
10.1016/j.jcat.2009.09.013
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发表时间：
2009-11-15
影响因子：
7.3
通讯作者：
Kasper, Gerhard
中科院分区：
文献类型：
--
作者：
Binder, Axel;Seipenbusch, Martin;Kasper, Gerhard
钯催化剂的合成在一个高度受控的化学气相沉积过程中，得到窄分布的Pd纳米粒子的中值尺寸范围从1.3到5 nm的SiO2或TiO 2支持。在常压固定床流动反应器中考察了Pd粒径和载体对乙烯加氢制乙烷反应的影响。发现TOF在3至4 nm处达到峰值，对载体材料具有弱依赖性。金属载体的相互作用一般较弱，表明密切匹配的活化能为20 kJ mol（-1）的非负载Pd，和28 kJ mol（-1）的二氧化钛和二氧化硅负载的催化剂。峰值TOF值随H-2分压系统地变化，表明Pd颗粒对反应性的显著体积效应。(C)2009 Elsevier Inc. All rights reserved.
Palladium catalysts were synthesized in a highly controlled chemical vapor deposition process, giving narrowly distributed Pd nanoparticles with median sizes ranging from 1.3 to 5 nm on a SiO2 or TiO2 support. Unsupported Pd nanoparticles with median sizes between 3 and 9 nm were also generated by spark discharge.The influence of Pd particle size and support on the hydrogenation of ethene to ethane was investigated in a fixed-bed flow reactor at atmospheric pressure. The TOF was found to peak at 3 to 4 nm with a weak dependence on the support material. Metal support interactions were generally weak, indicated by closely matching activation energies of 20 kJ mol(-1) for unsupported Pd, and 28 kJ mol(-1) for titania and silica supported catalysts. Peak TOF values varied systematically with H-2 partial pressure, indicating a pronounced volume effect of the Pd particles on the reactivity. (C) 2009 Elsevier Inc. All rights reserved.