费托合成制低碳烯烃中碱金属对CoMn催化剂催化性能的影响  

Effects of alkalis on the catalytic performance of CoMn catalysts for Fischer-Tropsch to olefin reactions

作　　者：杨若欧 孙凡飞[2] 赵子昂 赵景泰[1] 姜政[2] YANG RUOOU;SUN Fanfei;ZHAO Ziang;ZHAO Jingtai;JIANG Zheng(School of Materials Science and Engineering,Shanghai University,Shanghai 201900,China;Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Zhangjiang Campus,Shanghai 201204,China;Dalian National Laboratory for Clean Energy,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China)

机构地区：[1]上海大学材料科学与工程学院,上海201900 [2]中国科学院上海应用物理研究所张江园区,上海201204 [3]中国科学院大连化学物理研究所清洁能源国家实验室,大连116023

出　　处：《核技术》2018年第10期8-13,共6页Nuclear Techniques

基　　金：国家自然科学基金联合基金项目(No.U1732267);国家自然科学基金(No.91545101)资助~~

摘　　要：碳化钴(Co2C)在费托合成制低碳烯烃(Fischer-Tropsch to Olefin, FTO)中起着重要的催化作用。通过X射线衍射(X-ray Diffraction, XRD)、X射线吸收精细结构(X-ray Absorption Fine Structure, XAFS)等表征与方法,对碱金属在CoMn催化FTO中形成碳化钴的影响进行了研究。在钠(Na)、钾(K)元素的影响下,CoMn催化剂在活性评测中,低碳非饱和烃与低碳饱和烃的比例高达17.4与9.4,且仅有较低的甲烷(CH4)产生,而锂(Li)对CoMn催化剂的选择性影响较弱。通过XRD表征,发现Na、K对CoMn催化剂形成Co2C有很好的促进效果。XAFS揭示了CoMn催化剂的电子结构,催化反应后形成碳化钴的配位结构,为研究CoMn催化剂微观结构提供了基础理论。[Background] Cobalt carbide（Co2C） has recently been reported to catalyze the Fischer-Tropsch to olefin（FTO） conversion of syngas with high selectivity. However, electronic state and coordination structure of cobalt carbide is limited by its complex reaction. [Purpose] This study aims to clarify the effect of alkalis of CoMn catalysts for FTO and understanding the atomic structure of cobalt carbide nanoparticles in the CoMn catalyst. [Methods] X-ray absorption fine structure（XAFS） experimental on beamline（BL14W1） of XAFS spectroscopy at the Shanghai Synchrotron Radiation Facility（SSRF） is conducted to explore the electronic state and coordination structure of cobalt carbide with the effects of alkalis. [Results] X-ray absorption near-edge structures（XANES） spectra indicts that Na, K acted as electronic donors to cobalt than Li. EXAFS spectra clarified show that the atomic structure of cobalt carbide nanoparticles. [Conclusion] The Na, K promoter had benefited the formation of the cobalt carbide in the evolution of the FTO catalysts.

关 键 词：费托合成制低碳烯烃 碳化钴 碱金属 X射线吸收精细结构谱 

分 类 号：TL99[核科学技术—核技术及应用]