Abstract:

Using carbon monoxide and acetylene as probe molecule, their adsorption and acetylene hydrogenation on Pd-Ag/ Al₂O₃ and Pd/ Al₂O₃ catalysts were studied by in-situ DRIFTS.Hydrogenation of acetylene and CO chemisorptions properties over surface of catalysts were investigated.The results showed that the catalyst surface state and its properties were changed by addition of Ag into Pd/ Al₂O₃ due to both geometric and electronic effects.During adsorption and hydrogenation of acetylene, formation of carbonaceous layer that may become green oil and have great effect on the reaction selectivity to ethylene, was observed on catalyst surface.From the infrared spectra, long-chain alkane was tentatively identified as being present in the carbonaceous layer.

Key words: FONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-font-family: Times New Roman, mso-bidi-font-family: Times New Roman, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">原位红外光谱；乙炔；加氢；金属催化剂；钯

摘要：

以一氧化碳和乙炔为探针分子，采用原位红外光谱技术研究了Pd-Ag/ Al₂O₃和Pd/ Al₂O₃催化剂上乙炔加氢反应以及催化剂本身的表面形态，动态考察了乙炔加氢的气相反应行为、CO吸附以及催化剂表面吸附物种的变化。结果表明，在Pd-Ag/ Al₂O₃催化体系中，由于Ag的加入而受到几何效应和电子效应的共同影响，引起了催化剂表面形态的改变从而改变了催化剂的性能。另外，乙炔加氢反应会导致钯催化剂表面形成由长分子链的饱和烃组成的碳氢化合物层，该碳氢化合物层有可能是加氢反应形成的绿油。

关键词: FONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-font-family: Times New Roman, mso-bidi-font-family: Times New Roman, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">原位红外光谱；乙炔；加氢；金属催化剂；钯