Metal and nitrogen–doped carbon electrocatalysts (M–N–C, where M is Fe or Co) were investigated for the oxygen reduction reaction (ORR) in alkaline conditions in the presence of borohydride ions (BH₄⁻). The electrochemical properties of the Fe–N–C and Co–N–C catalysts were investigated by cyclic voltammetry and rotating disk electrode techniques: their ORR electrocatalytic activity was bridged to their physicochemical properties, mainly type of metallic center (Fe vs. Co), structure (atomic dispersion vs. nanoparticles), and BET surface area. It is found that Fe–N–C catalysts have the best performances for the ORR electrocatalysis, even in the presence of BH₄⁻ anions. The atomically dispersed Fe- and Co-containing electrocatalysts reach better BH₄⁻-tolerance than their counterparts baring nanoparticles. For the atomically dispersed Fe–N–C electrocatalysts, the lowest BET surface area material generates a slight advantage of ORR mass activity and a poor (and desired) activity for borohydride oxidation reaction (BOR).

Graphical Abstract

金属和氮掺杂的碳电催化剂（M-N-C，其中中号为Fe或Co）进行了调查，在硼氢化物离子的存在下在碱性条件中的氧还原反应（ORR）（BH ₄ ^- ）。通过循环伏安法和旋转盘电极技术研究了Fe–N–C和Co–N–C催化剂的电化学性质：它们的ORR电催化活性与它们的物理化学性质有关，主要是金属中心的类型（Fe与Co） ，结构（原子分散体与纳米颗粒的关系）和BET表面积。可知的Fe-N-C催化剂具有为ORR电催化最好的性能，即使在BH的存在下₄ ^-阴离子。以原子分散含Co的Fe和电催化剂达到更好的BH ₄ ^- -公差比他们的同行霸菱纳米粒子。对于原子分散的Fe–N–C电催化剂，最低的BET表面积材料产生ORR质量活性的轻微优势，而硼氢化物氧化反应（BOR）的活性较差（且理想）。

图形概要