氮掺杂碳载非贵金属复合材料的构建及其电催化硼氢化钠氧化性能研究

The direct borohydride fuel cell (DBFC) has been extensively studied for many advantages, such as high fuel efficiency, easily to transport and conveniently to storage, no catalytic poisoning, and envitonmentally friendly. Moreover, DBFC has high theoretical open circuit voltage (1.64 V), high theoretical capacity (5.67 Ah/g) and energy convert efficiency (91%) .The anode electrocatalyst is the key component in DBFC. In this proposal, we will focus on the design and synthesis of novel N-doped carbon supported non-noble metal composites.The chemical composition, structures, physical and electrochemical properties of the synthesized electrocatalysts, and the electrocatalytic mechanisms for BH4ˉ electrooxidation and hydrolysis reactions will be studied. The influence factors for the catalytic activity and stability of the catalysts, such as microstructure of catalysts and supports, bonding mechanism between catalysts and supports, experiment conditions during loading catalysts on supports. We will try to reveal the inter-correlation among these factors, and the relationship between these factors and the electrccatalytic performance of N-doped carbon supported non-noble metal composites. Furthermore, the mechanism for the decrease of catalytic activity and the increase of efficiency for the catalysts will be illuminated to develop new DBFC anode electrocatalysts with low cost, good catalytic performance, and long-term durability .Half-cell and single-cell testing devices will be designed and the electrocatalytic mechanisms for the anode electrooxidation reaction will be studied by electrochemical method, combined with current physical and chemical methods.The above studies would provide theoretical foundation and technological instruction for design and synthesis novel anode materials and develop new electrocatalysts fof DBFC.

直接硼氢化钠燃料电池(DBFC)因其燃料效率高，燃料运输存储方便、无催化剂中毒，产物无污染且理论电压(1.64 V)、理论比容量(5.67 Ah/g)和能量转化率(91%)高而备受关注。DBFC商业化应用的关键是发展廉价高效的阳极电催化剂。本项目拟设计并制备氮掺杂碳载非贵金属复合材料催化剂，通过研究催化剂的组成、结构和性能的关系，探讨催化剂对BH4ˉ氧化反应和水解反应的催化机理，研究催化剂和载体的微观结构和表面状态、催化活性组分与载体的键合机制及催化活性组分的负载工艺等对催化剂活性和稳定性的影响，揭示各因素相互之间及其与电催化活性之间的作用规律，阐明催化剂性能衰减和效能提高的机制，发展廉价、高效、稳定性好的阳极催化剂。设计半电池和单体电池测试装置，利用电化学方法，结合现代物理化学研究手段进行系统研究，为优化和完善燃料电池电极材料制备技术，发展新型催化剂提供理论依据和实验方法指导。

直接硼氢化钠燃料电池(DBFC)主要以Pt、Au、Pd等贵金属作阳极催化剂，高的催化剂成本阻碍了DBFC的商业化。本项目针对限制DBFC商业化的瓶颈问题，从新型氮掺杂碳载金属催化剂和金属氧化物复合材料催化剂的研发两方面着手，提高催化剂性能，降低其成本。主要研究了以下两部分内容：.1. 设计和制备了氮掺杂碳-碳纳米管载Co催化剂 (Co/NC-CNT)，氮掺杂多孔碳载AuFe催化剂(AuFe/N-C)，氮掺杂石墨烯载AuCu催化剂(AuCu/N-rGO)和氮掺杂碳包裹AuCo催化剂（AuCo@NC）。采用X-射线衍射(XRD)，扫描电镜（SEM），透射电镜(TEM)，X-射线光电子能谱(XPS)，X-射线能谱(EDS)等研究了催化剂及氮掺杂碳载体的组成、结构、形貌；采用循环伏安(CV)，计时电流(CA)，交流阻抗(EIS)等研究了催化剂对硼氢化钠电催化氧化反应的催化特性；研究了催化剂和载体的微观结构，表面形态，催化剂活性组分，载体的比表面积等对催化剂活性与稳定性的影响。研究结果表明，采用新型氮掺杂碳材料作催化剂载体，催化剂的催化活性和稳定性均得到了提高。3d过渡态金属掺杂能明显提高贵金属催化剂的催化活性，XPS结果表明其原因是双金属之间的电子效应。.2. 设计和制备了Fe2O3@Co3O4和Co3O4/NiO等不同形貌的新型金属氧化物复合材料，采用XRD，SEM， TEM，XPS，EDS等研究了新型金属氧化物复合材料催化剂的组成，结构，形貌。采用CV，CA，EIS等研究了催化剂对硼氢化钠电催化氧化反应的催化特性；探讨了结构、形貌、组成、煅烧温度等对催化剂性能的影响。研究结果表明，廉价的金属氧化物具有较好的催化活性，进一步拓展了DBFC用阳极催化剂的范围。