柠檬酸对Ni-W焦化蜡油加氢处理催化剂性能的影响

以含改性HY分子筛的TiO₂-SiO₂复合氧化物为载体，以Ni、W为活性金属组分，采用等体积溶液浸渍法制得了焦化蜡油加氢处理催化剂，考察了浸渍液中加入柠檬酸对催化剂性质及加氢精制性能的影响。BET、FT-IR、XRD、UV-Vis DRS和TG-DSC等表征结果表明，柠檬酸与金属组分间的络合作用提高了金属活性组分的分散度，改变了金属组分的存在状态，促进了单一形式的聚钨酸盐和高活性的六配位八面体Ni物种的形成。柠檬酸改性的Ni-W系催化剂对焦化蜡油的加氢精制性能明显改善，尤其是加氢脱氮性能得以大幅度提高。

Effect of citric acid on Ni-W catalysts for hydrotreatment of coking gas oil

Ni-W/CYCTS4 catalysts for coking gas oil(CGO) hydrotreating were prepared by the isovolumic impregnation method using nickel-tungstate as active metals.The composite supports were composed of TiO2-SiO2 complex oxides and modified Y zeolites.The properties of the catalyst modified by citric acid in the impregnation solution and the catalytic performance of hydrotreating coking gas oil were examined.The physical and chemical properties of the catalysts were investigated with BET,FT-IR,XRD,UV-Vis DRS and TG-DSC.The results indicated that citric acid as complexing agent could increase the dispersion degree of active species in catalysts.At the same time,citric acid could change the state of active metals and promote the formation of single polytungstate species and highly active nickel species in octahedral sites.The hydrotreating performance of the Ni-W/CYCTS4 catalysts modified by citric acid for coking gas oil was remarkably promoted,especially the hydrodenitrogenation performance.