Fig. 4: Origin exploration of the enhancement in Usite and electrocatalytic performance.
From: Near-100% site utilization of single atoms for efficient electrocatalysis
a Schematic comparison of O2 diffusion pathways in 3D FeNC vs. 2D FeNC. The green ball-and-stick model represents the O2 molecules, and the red arrow indicates the direction of MT. b Pore volume distribution and c Cdl_CV, Cdl_EIS, Cdl_CV/Cdl_EIS for catalysts. d Potential-dependent Rct (left) and Rmt (right) of 3D FeNC and 2D FeNC from operando hydrodynamic EIS. e DRT analysis of 3D FeNC and 2D FeNC at different potentials. f FEM-simulated O2 concentration profiles across 3D FeNC (top) and 2D FeNC (bottom) models (1–15 ms timeframe). g In situ ATR-FTIR spectra of 3D FeNC (top) and 2D FeNC (bottom) under applied potentials.
