Atomic Tuning of Single-Atom Fe–N–C Catalysts with Phosphorus for Robust Electrochemical CO₂ Reduction

Abstract

The electrochemical reduction of CO2 to produce carbon-based fuels and chemicals possesses huge potentials to alleviate current environmental problems. However, it is confronted by great challenges in the design of active electrocatalysts with low overpotentials and high product selectivity. Here we report the atomic tuning of a single-Fe-atom catalyst with phosphorus (Fe–N/P–C) on commercial carbon black as a robust electrocatalyst for CO2 reduction. The Fe–N/P–C catalyst exhibits impressive performance in the electrochemical reduction of CO2 to CO, with a high Faradaic efficiency of 98% and a high mass-normalized turnover frequency of 508.8 h–1 at a low overpotential of 0.34 V. On the basis of ex-situ X-ray absorption spectroscopy measurements and DFT calculations, we reveal that the tuning of P in single-Fe-atom catalysts reduces the oxidation state of the Fe center and decreases the free-energy barrier of *CO intermediate formation, consequently maintaining the electrocatalytic activity and stability of single-Fe-atom catalysts.

Unveiling the Proton‐Feeding Effect in Sulfur‐Doped Fe−N−C Single‐Atom Catalyst for Enhanced CO2 Electroreduction

“…Chemie cussions, the S-doping in the second shell of FeN 4 boosts the CO 2 electroreduction to CO with regard to the pristine FeN 4 . Notably, the Fe-based SAC usually shows a small current density of CO 2 RR in recent reports [5,22,[49][50][51] due to the sluggish CO 2 RR kinetics. Such an S-doping strategy plays an essential role in improving CO 2 RR kinetics and breaking the limitation of enhancing CO 2 RR performance for Fe-based SAC.…”

Boosting the oxygen reduction reaction behaviour of atomic Fe–N4active sites in porous honeycomb-like carbonviaP heteroatom doping

“…The EXAFS spectrum was satisfactorily fitted using the Fe–N backscattering pathway, and the main broad peak at ∼ 1.53 Å in the R space of the FT-EXAFS spectrum could be attributed to the backscattering of Fe–N first-shell coordination. 3 The average coordination number of the N atoms was determined to be 4.1. Therefore, the experimental results confirmed that the SAs were coordinated with four N atoms to generate the Fe–N 4 square-planar configuration.…”

“…The signicantly increased consumption of fossil fuels and critical environmental concerns have encouraged the pursuit of environment-friendly and renewable energy technologies. [1][2][3][4][5] Fuel cells and metal-air batteries with the merits of low emission, high energy density and superior energy conversion efficiency support pivotal approaches to clean energy challenges. [6][7][8][9][10][11][12][13] An essential step that signicantly limits the performance of these devices is the cathodic oxygen reduction reaction (ORR), which depends heavily on the electrocatalysts containing platinum group metals (PGMs).…”

Unveiling the Proton‐Feeding Effect in Sulfur‐Doped Fe−N−C Single‐Atom Catalyst for Enhanced CO2 Electroreduction

“…cussions, the S-doping in the second shell of FeN 4 boosts the CO 2 electroreduction to CO with regard to the pristine FeN 4 . Notably, the Fe-based SAC usually shows a small current density of CO 2 RR in recent reports [5,22,[49][50][51] due to the sluggish CO 2 RR kinetics. Such an S-doping strategy plays an essential role in improving CO 2 RR kinetics and breaking the limitation of enhancing CO 2 RR performance for Fe-based SAC.…”