Synthesis of Metal–Nitrogen–Carbon Electrocatalysts with Atomically Regulated Nitrogen-Doped Polycyclic Aromatic Hydrocarbons
Shaoqing Chen, Huimin Yan, Jochi Tseng, Shijie Ge, Xia Li, Lin Xie, Zian Xu, Pengfei Liu, Chongxuan Liu, Jie Zeng, Yang‐Gang Wang, Hsing‐Lin Wang
Abstract
Tuning the active site structure of metal–nitrogen–carbon electrocatalysts has recently attracted increasing interest. Herein, we report a bottom-up synthesis strategy in which atomically regulated N-doped polycyclic aromatic hydrocarbons (N-PAHs) of N x C 42– x ( x = 1, 2, 3, 4) were used as ligands to allow tuning of the active site’s structures of M–N x and establish correlations between the structures and electrocatalytic properties. Based on the synthesis process, detailed characterization, and DFT calculation results, active structures of N x –Fe 1 –N x in Fe 1 –N x /RGO catalysts were constructed. The results demonstrated that the extra uncoordinated N atoms around the Fe 1 –N 4 moieties disrupted the π-conjugated N x C 42– x ligands, which led to more localized electronic state in the Fe 1 –N 4 moieties and superior catalytic performance. Especially, the Fe 1 –N4/RGO exhibited optimized performance for ORR with E 1/2 increasing by 80 mV and J k at 0.85 V improved 18 times (compared with Fe 1 –N1/RGO). This synthesis strategy utilizing N-PAHs holds significant promise for enhancing the controllability of metal–nitrogen–carbon electrocatalyst preparation.