乙醇在Ni－Pb／C催化剂上羰化反应机理的研究

Study on the Mechanism or Ethanol Oxo-reaction on Ni-Pb/C Catalyst

本文对乙醇在Ｎｉ－Ｐｂ／Ｃ催化剂上羰化反应的机理进行了研究，通过Ｘ－光电子能谱（ＸＰＳ）和Ｘ－射线衍射（ＸＲＤ）对反应前后的催化剂进行了表征．得出了Ｎｉ催化剂的活性中心是零价的金属Ｎｉ，加入Ｐｂ使更多的Ｎｉ（２＋）还原成Ｎｉ０，增加了活性中心的数量。Ｈ２起着还原Ｎｉ（２＋）和使Ｎｉ０富集的双重作用，ＣＯ在反应过程中使富集的金属分散开来，Ｃ２Ｈ２Ｉ则使散开的催化活性位得到稳定。Ｐｂ的加入通过载体与Ｎｉ之间电荷传送，减少了Ｎｉ氧化态与还原态间的能量差，促进了Ｎｉ在反应中的循环，提高了催化剂的活性．

The mechanism of ethanol oxo-reaction on Ni-Pb/C catalgst was studied through characterization of the catalyst before and after oxo-reaction with XPS and XRD.The study showed that Ni0 is the active centre of Ni catalyst; addition of Pb makes more Ni2+ to be reduced to Ni0 and thus increase the number of active centres; H2 has double function of both reducing Ni2+ and enriching Ni0;CO scatters the enriched metal during reaction while C2H5I stabilizes the dispersed active sites. Addition of Pb narrows the energy gap between oxided and reduced nickel through electric charge transfer between support and nickel,promotes circulation of nickel during reaction and euhances the catalytic activity.