物理化学学报2023，Vol.39Issue(11)：4-10,7.DOI:10.3866/PKU.WHXB202301012
间隙碳调控Ni实现1,3-丁二烯高效加氢
Interstitial Carbon in Ni Enables High-Efficiency Hydrogenation of 1,3-Butadiene
摘要
Abstract
Selective hydrogenation is an essential catalytic reaction in modern industrial chemistry.For instance,butene can be used to produce many important organic chemical products,but the catalytic cracking of naphtha to produce olefins also produces some diolefins,which contain approximately 0.2%-2.0%1,3-butadiene.The selective hydrogenation of 1,3-butadiene is a crucial step in purifying single olefins and prevents poisoning of the catalysts used in polymerization.Currently,the most common industrially employed catalysts in the reaction are palladium-based catalysts,but drawbacks associated with these include high cost and low abundance.Transition metal Ni-based catalysts have the advantages of being low cost and having high hydrogenation activity,but they are prone to excessive hydrogenation in butadiene hydrogenation reactions.This leads to reduced selectivity and the loss of monoolefins in the feed gas.In addition,Ni-based catalysts tend to accumulate carbon on the surface,which results in catalyst deactivation.Therefore,designing Ni-based catalysts with excellent catalytic performance has been an industrial research priority.Herein,we synthesized Ni3Zn/Al2O3 catalysts by impregnation and achieved the alumina-supported Ni3ZnC0.7 structure by acetylene atmosphere treatment.Interstitial sites of the Ni3Zn intermetallic catalyst were modified by introducing interstitial carbon atoms.This enhances the catalytic performance of the 1,3-butadiene hydrogenation reaction.X-ray diffraction and transmission electron microscopy revealed that the catalyst presents a typical Ni3ZnC0.7 phase.The interstitial carbon structure can suppress excessive hydrogenation,exhibiting up to 93%butene selectivity at a 98%conversion of 1,3-butadiene,which renders it superior to the Ni3Zn/Al2O3 catalyst.More importantly,the selectivity to 1-butene is improved by approximately 40%compared to the Ni3Zn/Al2O3 intermetallic catalyst.In addition,the Ni3ZnC0.7/Al2O3 catalyst exhibits superior and stable selectivity within a wide H2/1,3-butadiene ratio range and can operate reliably under fluctuating conditions.CO-diffuse reflectance infrared Fourier transformed spectroscopy(CO-DRIFTS)demonstrated that coordinating the carbon atom in the interstitial site with the neighboring Ni atoms alters the electron structure of the Ni sites in the Ni3ZnC0.7 structure.The electrons at the surface Ni sites are transferred to the carbon atoms at the interstitial sites rendering Ni more electron-deficient and decreasing the adsorption strength of 1-butene,which inhibits the excessive hydrogenation reaction pathway.It is also noteworthy that the interstitial carbon structure can inhibit carbonaceous species formation and accumulation significantly improving the Ni3ZnC0.7/Al2O3 catalyst's stability.This work is significant for understanding the structure-performance relationship at the interstitial sites in transition metal catalysts.Furthermore,it provides new insights into the design of hydrogenation catalysts.关键词
镍基催化剂/间隙位点/Ni3ZnC0.7/选择性加氢/亚表面碳Key words
Ni-based catalyst/Interstitial site/Ni3ZnC0.7/Selective hydrogenation/Subsurface carbon分类
化学引用本文复制引用
董少明,普颖慧,牛一鸣,张蕾,王永钊,张炳森..间隙碳调控Ni实现1,3-丁二烯高效加氢[J].物理化学学报,2023,39(11):4-10,7.基金项目
国家自然科学基金(22072164,22002173,52161145403)与沈阳材料科学国家研究中心基金资助项目 The project was supported by the National Natural Science Foundation of China(22072164,22002173,52161145403)and the Research Fund of Shenyang National Laboratory for Materials Science,China. （22072164,22002173,52161145403）
