ZIFs材料对Fe/N/C催化剂氧还原性能的影响  

Effect of ZIFs Materials on the Oxygen Reduction Performance of Fe/N/C Catalysts

作　　者：宋冬梅 郑秋燕 潘廷仙 胡长刚[1,2] 同鑫 田娟[1,2] SONG Dongmei;ZHENG Qiuyan;PAN Tingxian;HU Changgang;TONG Xin;TIAN Juan(School of Chemistry and Material Science,Guizhou Normal University,Guiyang 550001,China;Key Laboratory for Functional Materials Chemistry of Guizhou Province,Guiyang 550001,China)

机构地区：[1]贵州师范大学化学与材料科学学院,贵阳550001 [2]贵州省功能材料化学重点实验室,贵阳550001

出　　处：《材料导报》2024年第10期45-51,共7页Materials Reports

基　　金：国家自然科学基金(21965006,22005072);中国科学院燃料电池及复合电能源重点实验室开放课题(KLFC201703)。

摘　　要：过渡金属/氮/碳(M/N/C)催化剂是替代铂基催化剂用于氧还原反应(ORR)的理想材料。沸石咪唑骨架(ZIFs)材料结合了无机沸石的高稳定性和MOFs材料的高比表面积、高孔隙率及可调孔结构等特点,是制备M/N/C催化剂的优良前驱体。本工作以FeSO4·7H2O为铁源,1,10-菲啰啉为氮源,探究不同ZIFs材料对FeN/C-Zx催化剂ORR性能的影响。通过X射线衍射、比表面积和孔径分布测试、透射电子显微镜等对催化剂进行结构表征,使用线性扫描伏安法对催化剂ORR催化活性进行测试。结果表明:FeN/C-Z8催化剂表现出最佳的ORR活性,具有较小的Tafel斜率(64.98 mV/dec)且反应过程是近四电子过程;在经过25000次循环后,FeN/C-Z8催化剂的半波电位仅有20 mV的负移,表现出良好的稳定性。FeN/C-Z8催化剂中存在的Fe3C化合物可有效提高催化剂的催化性能;Zn2+在碳化过程中挥发使FeN/C-Z8催化剂具有较高比表面积(550.09 m2/g)、孔体积(1.36 cm3/g)及丰富的微孔、介孔结构,并促进了过渡金属在ZIFs材料上的均匀分布,使FeN/C-Z8催化剂颗粒较小、分散均匀,这是该催化剂表现出较好的ORR催化性能的可能原因。Transition metal/nitrogen/carbon(M/N/C)catalysts are the most promising candidates to replace platinum-based catalysts for oxygen reduction reaction(ORR).Zeolitic imidazolate frameworks(ZIFs)are ideal precursors for the preparation of M/N/C catalysts since they combine the high stability of inorganic zeolites and the high specific surface area,high porosity,and tunable pore structure of MOFs materials.In this work,FeN/C-Z x catalysts were synthesized using FeSO 4·7H 2O,1,10-phenanthroline,and ZIFs as iron,nitrogen,and carbon precursors,respectively.The effect of using different ZIFs as carbon precursors on the ORR activity of FeN/C-Z x catalysts were investigated.The structure of the catalyst was characterized by X-ray diffraction,specific surface area and pore size distribution test,and transmission electron microscope.The catalytic activity of the catalyst for ORR was tested by linear scanning voltammetry.The results show that the FeN/C-Z 8 catalyst exhibits the best ORR activity,a small Tafel slope(64.98 mV/dec)with a nearly four-electron reaction process,and a good stability with only 20 mV negative shift in half-wave potential after 25000 cycles of accelerated degradation tests.The Fe 3C compound,which can effectively improve the catalytic activity,present in the FeN/C-Z 8 catalyst;the high specific surface area(550.09 m 2/g)and pore volume(1.36 cm 3/g),the abundant micropore and mesoporous structure,as well as the uniform distribution of transition metals on the ZIFs materials and the small catalyst particles size due to the volatilization of Zn 2+during the carbonization process,are the possible reasons to increase the ORR catalytic performance of FeN/C-Z 8 catalyst.

关 键 词：氧还原反应 非贵金属催化剂 沸石咪唑骨架 FeN掺杂 

分 类 号：O643.36[理学—物理化学]