Meng Hongjie, Pei Supeng, Li Hong, Zhang Yongming
School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Lab of Electrical Insulation and Thermal Aging, Center of Hydrogen Science, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, P. R. China.
ACS Omega. 2021 Apr 14;6(16):11059-11067. doi: 10.1021/acsomega.1c01024. eCollection 2021 Apr 27.
The stability and activity of the catalysts are crucial for the oxygen reduction reaction (ORR) in fuel cells. Herein, CoFe/N, S-codoped biomass carbon (FB-CoFe-700) with graphitic nanoribbons and multiple CoFe nanoparticles was prepared through a facile thermal pyrolysis followed by an acid treatment process. The evolution of the growth of metal nanoparticles with the formation of graphite during the carbonization process was investigated. Inseparable from graphitic carbon-encased metal nanoparticles with the coexistence of graphitized nanoribbons and graphene-like sheets, FB-CoFe-700 exhibited a remarkable long-term electrocatalytic stability with 90.7% current retention after 50 000 s much superior to that of the commercially available Pt/C (20 wt %) in an alkaline medium. Meanwhile, FB-CoFe-700 displayed promising ORR catalytic activity ( = 0.92 V vs reversible hydrogen electrode (RHE), = 0.82 V vs RHE, and = 3.97) very similar to that of commercial Pt/C and outstanding methanol tolerance in an alkaline medium. This work is helpful for further development of nonprecious metal-doped carbon electrocatalysts with long-term stability.
催化剂的稳定性和活性对于燃料电池中的氧还原反应（ORR）至关重要。在此，通过简便的热解然后进行酸处理过程，制备了具有石墨纳米带和多个CoFe纳米颗粒的CoFe/N、S共掺杂生物质碳（FB-CoFe-700）。研究了碳化过程中金属纳米颗粒的生长与石墨形成的演变。FB-CoFe-700与石墨化纳米带和类石墨烯片共存的石墨碳包裹金属纳米颗粒不可分离，在碱性介质中表现出显著的长期电催化稳定性，50000 s后电流保留率为90.7%，远优于市售的Pt/C（20 wt%）。同时，FB-CoFe-700表现出有前景的ORR催化活性（相对于可逆氢电极（RHE）， = 0.92 V， = 0.82 V， = 3.97），与市售Pt/C非常相似，并且在碱性介质中具有出色的甲醇耐受性。这项工作有助于进一步开发具有长期稳定性的非贵金属掺杂碳电催化剂。
