基于掺氮石墨烯的高性能Fe-N-C非铂燃料电池催化剂的制备与表征

Limited supply and high cost of platinum become the key factor to the large-scale usage of proton exchange membrane fuel cells, indicating that non-platinum catalysts will be the only choice to achieve the commercialization of fuel cell car. This proposal aims to explore the preparation, characterization, and application of nitrogen-doped graphene-based Fe-N-C catalyst by intermittent microwave using graphite nano-sheets, Fe precursor under ammonia atmosphere. A large number of defects in graphene synthesized by graphite oxide and the rapid temperature increase by the microwave absorbing ability of carbon will benefit to the formation of Fe-N-C with a high activity. The performance of Fe-N-C on oxygen reduction reaction, single cell and stability test will be systematically evaluated and related to its preparation and micro-structure. In addition, the unique property of Fe-N-C as methanol-tolerant catalyst in the cathode of direct methanol fuel cell will be employed to improve its performance and Faraday efficiency. Therefore, combination of the microwave method and the graphene-based Fe-N-C, we were able to prepare non-noble catalysts with high activity, high stability, and high selectivity. Through the conduct of this project, the relationship between the performance and the micro-structure of the non-noble metal catalyst will be explored in-depth and certain rules for the design and practical applications of the high-performance non-noble metal catalyst can be provided.

铂的有限储量和高昂价格一直制约着质子交换膜燃料电池的发展，而非铂催化剂的性能最近几年获得了长足进步，尤其是铁氮碳（Fe-N-C）非铂催化剂引起了广泛关注。本项目旨在利用石墨烯边缘官能团丰富的特点,在石墨烯中引入含氮原子，从而增加石墨烯表面吸附金属粒子的活性位，进而提高石墨烯的自由载流子密度并增强金属粒子与石墨烯的相互作用。同时利用碳材料吸收微波而迅速升温的特点，制备基于大比表面掺氮石墨烯的高性能Fe-N-C非铂催化剂。通过关联Fe-N-C的结构与氧还原电化学性能的关系，揭示出制备高反应活性非铂催化剂的关键因素。在此基础上，优化基于非铂催化剂的膜电极结构，提高电池性能和长时间放电稳定性。通过本项目的开展，可深入探索非贵金属催化剂的活性、稳定性和选择性与催化剂的微结构之间的关系，为高性能非贵金属催化剂的设计和实际应用提供规律性结果。

铁氮碳（Fe/N/C）非铂催化剂的氧还原活性和稳定性正逐步接近铂碳催化剂，近年来该研究方向受到了燃料电池研究及应用领域的广泛关注。在本基金的支持下，重点研究了以下几种新型掺氮石墨烯氧还原催化剂，采用固相聚合法合成了对苯二胺前驱体，利用纳米ZnO为模板制备了高活性的氧还原催化剂；通过对Fe/N/C掺氮石墨烯催化剂的表面进行CeO2修饰，减少了自由基对催化剂的伤害，大幅提高了催化剂稳定性；利用熔融盐法热解均苯四甲基酸酐-三聚氰胺树脂得到了高性能掺氮石墨烯催化剂；通过合成三聚氰胺甲醛树脂（MF）-碳黑复合材料，以及直接利用MF固体废弃物分别热解制备了低成本的掺氮石墨烯氧还原催化剂，并利用吐温80溶液对碳黑的分散作用显著提升了催化剂的活性；以核糖为碳源制备了高比表面的掺杂石墨烯非贵金属氧还原催化剂；以ZIF-8为前驱体，引入氧化石墨烯载体制备了非贵金属电催化剂；以卟啉铁为前驱体制备了高稳定性的掺氮石墨烯催化剂。项目执行期内，主办了1个国际学术会议（2017中英低铂和非铂催化剂在质子交换膜燃料电池的应用研究双边研讨会），参加了19个国内外学术会议；发表学术论文16篇（均已标注项目编号：21476104），其中SCI论文15篇；申请发明专利2项；培养博士后1名，博士研究生2名，硕士研究生5名。