College of Chemistry and Chemical Engineering, State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen, 361005, P. R. China.
Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, 10691, Sweden.
ChemSusChem. 2022 Mar 8;15(5):e202102587. doi: 10.1002/cssc.202102587. Epub 2022 Jan 31.
The impact of pore structure on the two-electron oxygen reduction reaction (ORR) in nitrogen-doped carbon materials is currently under debate, and previous studies are mainly limited to the rotating ring-disk electrode (RRDE) rather than the practical flow cell (FC) system. In this study, assisted by a group of reliable pore models, the impact of two pore structure parameters, that is, Brunauer-Emmett-Teller surface area (S ) and micropore surface fraction (f ), on ORR activity and selectivity are investigated in both RRDE and FC. The ORR mass activity correlates positively to the S in the RRDE and FC because a higher S can host more active sites. The H O selectivity is independent of f in the RRDE but correlates negatively to f in the FC. The inconsistency results from different states of the electrode in the RRDE and the FC. These insights will guide the design of carbon materials for H O synthesis.
孔结构对氮掺杂碳材料中两电子氧还原反应（ORR）的影响目前存在争议，先前的研究主要限于旋转环盘电极（RRDE）而不是实际的流动电池（FC）系统。在这项研究中，借助一组可靠的孔模型，研究了两个孔结构参数，即 Brunauer-Emmett-Teller 比表面积（S）和微孔表面积分数（f），对 RRDE 和 FC 中 ORR 活性和选择性的影响。RRDE 和 FC 中的 ORR 质量活性与 S 呈正相关，因为较高的 S 可以容纳更多的活性位点。在 RRDE 中，H2O 选择性与 f 无关，但在 FC 中与 f 呈负相关。不一致的结果源于 RRDE 和 FC 中电极的不同状态。这些见解将指导用于 H2O 合成的碳材料的设计。
