Quantum mechanics

Catalysis

Spin states

Chemical physics

Electrochemistry

Photochemistry

Materials science

Embedded system

Protonation

Antibonding molecular orbital

Ammonia

Computer science

Inorganic chemistry

Atomic orbital

Electrocatalyst

Physical chemistry

Physics

Nanotechnology

Organic chemistry

Doping

Atom (system on chip)

Chemistry

Electrode

Electron

Optoelectronics

Ammonia production

Advanced Materials

The electrochemical nitrogen reduction reaction (e-NRR) is envisaged as alternative technique to the Haber-Bosch process for NH3 synthesis. However, how to develop highly active e-NRR catalysts faces daunting challenges. Herein, a viable strategy to manipulate local spin state of isolated iron sites through S-coordinated doping (FeSA -NSC) is reported. Incorporation of S in the coordination of FeSA -NSC can induce the transition of spin-polarization configuration with the formation of a medium-spin-state of Fe (t2g 6 eg 1), which is beneficial for facilitating eg electrons to penetrate the antibonding π-orbital of nitrogen. As a consequence, a record-high current density up to 10 mA cm-2 can be achieved, together with a high NH3 selectivity of ≈10% in a flow cell reactor. Both experimental and theoretical analyses indicate that the monovalent Fe(I) atomic center in the FeSA -NSC after the S doping accelerates the N2 activation and protonation in the rate-determining step of *N2 to *NNH.

Local Spin‐State Tuning of Iron Single‐Atom Electrocatalyst by S‐Coordinated Doping for Kinetics‐Boosted Ammonia Synthesis