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采用10%H2S/H2对Ni2P/SiO2催化剂进行预处理,利用X射线衍射、电感耦合等离子发射光谱、X射线光电子能谱、CO化学吸附、H2程序升温脱附、NH3程序升温脱附及活性评价等方法研究了H2S预处理对催化剂结构和氯苯加氢脱氯反应性能的影响.结果表明,即使在873K进行H2S预处理,Ni2P/SiO2催化剂体相结构及Ni2P晶粒大小没有发生变化,但导致Ni2P晶粒表面形成了磷硫镍相(NiPxSy),同时使表面溢流氢数量增加.硫物种的存在不仅阻塞了部分镍中心,使催化剂表面镍中心密度降低,也导致镍中心的缺电子性进一步增加.经H2S预处理后Ni2P/SiO2催化剂上氯苯加氢脱氯反应的转化频率(TOF)明显提高,这可能与催化剂表面Ni物种的缺电子性增强及溢流氢数量增多有关.
The Ni2P / SiO2 catalyst was pretreated with 10% H2S / H2. XRD, ICP-AES, X-ray photoelectron spectroscopy, CO chemisorption, temperature programmed desorption with H2, temperature programmed desorption Etc. The effect of H2S pretreatment on the catalyst structure and the hydrodechlorination reaction performance of chlorobenzene was studied.The results showed that the structure of Ni2P / SiO2 catalyst did not change with the Ni2P grain size even after H2S pretreatment at 873K, Which led to the formation of NiPxSy phase on the surface of Ni2P grains and increased the amount of surface overflowing hydrogen.The presence of sulfur species not only blocked part of the nickel center but also reduced the nickel center density on the catalyst surface and led to the electron deficient The conversion frequency (TOF) of the hydrodechlorination reaction of chlorobenzene on Ni2P / SiO2 catalyst pretreated by H2S is obviously increased, which may be related to the increase of electron deficiencies and the overflowing hydrogen of Ni species on the catalyst surface.