Kalnin Arseniy, Kharisova Ksenia, Lukyanov Daniil, Filippova Sofia, Li Ruopeng, Yang Peixia, Levin Oleg, Alekseeva Elena
Electrochemistry Department, St. Petersburg State University, 7/9 Universitetskaya nab., 199034 St. Petersburg, Russia.
State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China.
Nanomaterials (Basel). 2024 Nov 29;14(23):1924. doi: 10.3390/nano14231924.
The oxygen reduction reaction (ORR) plays a central role in energy conversion and storage technologies. A promising alternative to precious metal catalysts are non-precious metal doped carbons. Considerable efforts have been devoted to cobalt-doped carbonized polyacrylonitrile catalysts, but the optimization of their catalytic performance remains a key challenge. We have proposed a multifunctional active metal source strategy based on the cobalt complex with the ligand containing pyridine and azo-fragments. This complex simultaneously provides the nitrogenous environment for the Co atoms and acts as a blowing agent due to N extrusion, thus increasing the surface area and porosity of the material. This strategy provided the catalysts with a high surface area and pore volume, combined with the greater fraction of Co-N clusters, and a lesser amount and smaller size of Co metal particles compared to conventionally prepared catalysts, resulting in improved catalytic performance. In addition to strict 4-electron ORR kinetics and 383 mV overpotential, the novel catalysts exhibit limiting current values close to the Pt/C benchmark and greatly overcome the Pt in methanol tolerance. These results demonstrate the critical role of metal source structure and carbonization parameters in tailoring the structural and electrochemical properties of the catalysts.
氧还原反应(ORR)在能量转换和存储技术中起着核心作用。非贵金属掺杂碳是贵金属催化剂的一种有前景的替代物。人们已对钴掺杂的碳化聚丙烯腈催化剂投入了大量努力,但优化其催化性能仍然是一个关键挑战。我们提出了一种基于钴与含吡啶和偶氮片段配体的配合物的多功能活性金属源策略。这种配合物同时为钴原子提供含氮环境,并由于氮的挤出而充当发泡剂,从而增加了材料的表面积和孔隙率。与传统制备的催化剂相比,该策略为催化剂提供了高表面积和孔体积,同时具有更大比例的Co-N簇,以及更少数量和更小尺寸的Co金属颗粒,从而提高了催化性能。除了严格的4电子ORR动力学和383 mV的过电位外,新型催化剂的极限电流值接近Pt/C基准,并且大大克服了Pt在甲醇耐受性方面的不足。这些结果证明了金属源结构和碳化参数在定制催化剂的结构和电化学性能方面的关键作用。