【作者】 王锐；

【导师】 张传玲； 朱春华；

【作者基本信息】 合肥工业大学 ， 化学工程（专业学位）， 2024， 硕士

【摘要】 电化学能量转换技术可实现化学能和电能间的相互转化,是可再生清洁能源的关键技术。其中,加快转化反应的催化剂是电化学能量转换技术的核心,而目前商业化电催化剂多为贵金属,导致高成本。开发具有低成本和高效稳定的非贵金属电催化剂,有望推进金属-空气电池和电解水槽等可再生能源器件的商业化发展。金属有机框架（MOFs）衍生材料因具有高比表面积、可调节的化学成分和均匀的杂原子掺杂等特点而在能源转换领域成为研究热点。特别地,基于组装效应,利用静电纺丝技术辅助构筑的MOFs纳米基元组装体及其衍生一维催化剂表现出更优性能。实现电纺MOFs衍生材料微结构的可控调节,并阐明构效关系,将有望进一步提高其电催化性能。因此,本论文在利用静电纺丝技术组装MOFs并制备其衍生纳米管的基础上,通过对微结构进行进一步优化,包括金属化合物组分的选择、异质结构的构筑及多种类杂原子的掺杂等,以制备高性能非贵金属碳基电催化剂。具体研究内容及结果如下:1.开发了Fe/Cu双金属化合物嵌入的多孔碳纳米管用于电催化氧还原（ORR）。以间接纺丝法制备的Zn/Fe/Cu-MOF纳米管为前驱体构筑Fe、Fe N_x和Cu Fe₂O₄纳米颗粒嵌入的N掺杂多孔碳纳米管（Fe-Fe N_x-Cu Fe₂O₄@CN）。所构筑的一维多孔管状碳基底具有高比表面积、多级孔结构、高石墨化程度和均匀的杂原子掺杂等特点,有利于提高催化剂的导电性和结构稳定性,协同金属化合物间形成的异质界面,可进一步加快离子/电子传输,降低反应动力学,提高电催化活性。基于以上结构和组分优势,所制备的Fe-Fe N_x-Cu Fe₂O₄@CN在碱性电解质中电催化ORR时具有高半波电位(E_1/2)(E_1/2=0.872 V)和优良的循环稳定性(5000圈CV循环后E_1/2损失34 m V),优于商用Pt/C电极。进一步地,将Fe-Fe N_x-Cu Fe₂O₄@CN作为阴极材料组装成锌空电池（ZABs）,电池的开路电压高达1.492 V并能稳定循环112 h,证明以Fe-Fe N_x-Cu Fe₂O₄@CN作为阴极催化剂所组装的ZABs具有高电化学性能。2.开发了Fe/Ni双金属磷化物嵌入的多孔碳纳米管用于双功能电解水催化剂。协同间接纺丝法和溶剂反应构筑Fe-MOF@Ni-MOF核壳结构纳米管,进一步通过高温碳化和磷化反应,制备出Fe P、Fe₂P和Ni₂P嵌入的P/N掺杂多孔碳纳米管（Fe P/Fe₂P/Ni₂P@CN）。所构筑的一维管状碳基体具有多级孔结构和高比表面积,P/N原子掺杂能进一步提高碳基底的导电性并调节电子结构,加快离子传输速率,结合多催化活性位间存在的协同效应,共同增强Fe P/Fe₂P/Ni₂P@CN的电催化活性和稳定性。在碱性电解质条件下电催化HER和OER时,Fe P/Fe₂P/Ni₂P@CN在10m A·cm^-2的过电位(η₁₀)分别为195 m V和289 m V,并且经过5000圈循环测试后η₁₀仅有轻微的衰减（分别衰减23 m V和22 m V）,证明所制备的双功能电催化剂具有高催化活性和稳定性。更多还原

【Abstract】 Electrochemical energy conversion technology enables the conversion of chemical energy into electrical energy,making it a crucial technology for renewable energy.The catalyst that facilitates the conversion reaction is central to electrochemical energy conversion technology,but current commercial electrocatalysts are mostly made of precious metals,leading to high costs.Development of non-precious metal electrocatalysts with low cost,high efficiency and stability is promising for commercializing renewable energy devices like metal-air batteries and electrolyzers.Materials derived from metal-organic frameworks（MOFs）have become a focus of research in energy conversion due to their large specific surface area,adjustable chemical composition,and uniform doping with heteroatoms.In particular,leveraging the assembly effect,the nano-unit assembly of MOFs and its derived one-dimensional catalyst through electrospinning technology demonstrates enhanced performance.The control of microstructure in MOFs-derived materials and elucidation of the structure-activity relationship are anticipated to further enhance their electrocatalytic performance.Therefore,this study utilizes electrospinning technology for assembling MOFs and preparing their derived nanotubes to optimize microstructure,including selection of metal compound components,construction of heterogeneous structures,and doping with various heteroatoms,in order to fabricate high-performance non-precious metal carbon-based electrocatalysts.The specific research contents and results are as follows:1.Porous carbon nanotubes embedded with Fe/Cu bimetallic compounds have been developed for electrocatalytic oxygen reduction（ORR）.N-doped porous carbon nanotubes embedded with Fe,Fe N_x,and Cu Fe₂O₄nanoparticles were constructed using Zn/Fe/Cu-MOF nanotubes prepared by indirect spinning method as the precursor（Fe-Fe N_x-Cu Fe₂O₄@CN）.The one-dimensional porous tubular carbon substrate has the characteristics of high specific surface area,multistage pore structure,high graphitization degree and uniform heteroatom doping,which is conducive to improving the conductivity and structural stability of the catalyst,and can further accelerate the ion/electron transport,reduce the reaction kinetics,and improve the electrocatalytic activity.Based on the above structural and component advantages,the prepared Fe-Fe N_x-Cu Fe₂O₄@CN possesses high half-wave potential(E_1/2)(E_1/2=0.872 V)and excellent cyclic stability(E_1/2loses 34 m V after 5000 CV cycles)when electrocatalyzing ORR in alkaline electrolyte.Superior to commercial Pt/C electrodes.Further,Fe-Fe N_x-Cu Fe₂O₄@CN is used as the cathode material to assemble ZABs.The open circuit voltage of the battery is as high as 1.492 V and the stable cycle is 112 h.It is proved that ZABs assembled with Fe-Fe N_x-Cu Fe₂O₄@CN as cathode catalyst has high electrochemical performance.2.Porous carbon nanotubes embedded with Fe/Ni bimetallic phosphide were developed for dual-function water electrolytic catalysts.The Fe-MOF@Ni-MOF core-shell nanotubes were synthesized by indirect spinning method and solvent reaction.The P/N-doped porous carbon nanotubes（Fe P/Fe₂P/Ni₂P@CN）with Fe P,Fe₂P,and Ni₂P embedded were further synthesized by high temperature carbonization and phosphating.The one-dimensional tubular carbon matrix has multistage pore structure and high specific surface area,P/N doped carbon matrix can further improve the conductivity of carbon substrate,adjust the electronic structure,and accelerate the ion transport rate,and there is a synergistic effect between the multiple catalytic active sites,which jointly enhance the electrocatalytic activity and stability of Fe P/Fe₂P/Ni₂P@CN.When HER and OER were electrocatalyzed in alkaline electrolyte,the overpotential(η₁₀)of Fe P/Fe₂P/Ni₂P@CN at 10 m A·cm^-2was 195 m V and 289 m V,respectively,andη₁₀only decreased slightly（by 23 m V and 22 m V,respectively）after 5000 cycles.It is proved that the prepared bifunctional electrocatalyst has high catalytic activity and stability.更多还原