An XPS study of the Phillips Cr/silica polymerization catalyst
An XPS study of the Phillips Cr/silica polymerization catalyst
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DOI：
10.1016/0021-9517(82)90178-6
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发表时间：
1982-10
影响因子：
7.3
通讯作者：
R. Merryfield;M. Mcdaniel;G. Parks
中科院分区：
文献类型：
--
作者：
R. Merryfield;M. Mcdaniel;G. Parks
用x射线光电子能谱和化学方法对菲利普斯Cr/二氧化硅聚合催化剂进行了研究，并将结果与高压高压灭菌器的活度测量结果进行了比较。600 ~ 800℃o2后只发现了Cr(VI)，但350℃CO将其清晰地还原为Cr（II）。二价材料与乙烯接触，使结合能略有提高，成为活性聚合催化剂。用乙烯还原Cr（VI）产生了类似的结果。这表明Cr（II）为活性前体，其电子密度被乙烯降低。
The Phillips Cr/silica polymerization catalyst has been examined by means of X-ray photoelectron spectroscopy and chemical methods, and the results have been compared to activity measurements from a high-pressure autoclave. Only Cr(VI) was found after O2at 600–800 °C, but CO at 350 °C cleanly reduced this to Cr(II). On contact with ethylene, which increased the binding energy slightly, the divalent material became an active polymerization catalyst. Reducing Cr(VI) with ethylene produced similar results. This indicates Cr(II) as the active precursor and that its electron density is decreased by the ethylene.