School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, China.
Coordination Chemistry Institute, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing, 210023, China.
Chem Asian J. 2019 Apr 1;14(7):995-1003. doi: 10.1002/asia.201801776. Epub 2019 Feb 20.
Fe-Co-N-C electrocatalysts have proven superior to their counterparts (e.g. Fe-N-C or Co-N-C) for the oxygen reduction reaction (ORR). Herein, we report on a unique strategy to prepare Fe-Co-N-C-x (x refers to the pyrolysis temperature) electrocatalysts which involves anion-exchange of [Fe(CN) ] into a cationic Co -based metal-organic framework precursor prior to heat treatment. Fe-Co-N-C-900 exhibits an optimal ORR catalytic performance in an alkaline electrolyte with an onset potential (E : 0.97 V) and half-wave potential (E : 0.86 V) comparable to that of commercial Pt/C (E =1.02 V; E =0.88 V), which outperforms the corresponding Co-N-C-900 sample (E =0.92 V; E =0.84 V) derived from the same MOF precursor without anion-exchange modification. This is the first example of Fe-Co-N-C electrocatalysts fabricated from a cationic Co -based MOF precursor that dopes the Fe element via anion-exchange, and our current work provides a new entrance towards MOF-derived transition-metal (e.g. Fe or Co) and nitrogen-codoped carbon electrocatalysts with excellent ORR activity.
Fe-Co-N-C 电催化剂在氧还原反应（ORR）中优于其对应物（例如 Fe-N-C 或 Co-N-C）。在此，我们报告了一种独特的策略来制备 Fe-Co-N-C-x（x 指的是热解温度）电催化剂，该策略涉及在热处理之前通过阴离子交换将 [Fe(CN) 6 ] 3- 插入到阳离子 Co 基金属-有机骨架前体中。在碱性电解质中，Fe-Co-N-C-900 表现出最佳的 ORR 催化性能，其起始电位（E 1/2 ：0.97 V）和半波电位（E 1/2 ：0.86 V）可与商业 Pt/C（E =1.02 V；E =0.88 V）相媲美，优于来自相同 MOF 前体但未经阴离子交换修饰的相应 Co-N-C-900 样品（E 1/2 ：0.92 V；E 1/2 ：0.84 V）。这是首例通过阴离子交换掺杂 Fe 元素的阳离子 Co 基 MOF 前体制备的 Fe-Co-N-C 电催化剂，我们目前的工作为具有优异 ORR 活性的 MOF 衍生过渡金属（例如 Fe 或 Co）和氮掺杂碳电催化剂提供了一个新的途径。
