Tailoring the d-Band Center of WS2 by Metal and Nonmetal Dual-Doping for Enhanced Electrocatalytic Nitrogen Reduction.

ABSTRACT

Tuning the adsorption energy of nitrogen intermediates and lowering the reaction energy barrier is essential to accelerate the kinetics of nitrogen reduction reaction (NRR), yet remains a great challenge. Herein, the electronic structure of WS2 is tailored based on a metal and nonmetal dual-doping strategy (denoted Fe, F-WS2) to lower the d-band center of W in order to optimize the adsorption of nitrogen intermediates. The obtained Fe, F-WS2 nanosheet catalyst presents a high Faradic efficiency (FE) of 22.42% with a NH3 yield rate of 91.46 µg h-1 mgcat. -1. The in situ characterizations and DFT simulations consistently show the enhanced activity is attributed to the downshift of the d-band center, which contributes to the rate-determining step of the second protonation to form N2H2 * key intermediates, thereby boosting the overall nitrogen electrocatalysis reaction kinetics. This work opens a new avenue to enhanced electrocatalysis by modulating the electronic structure and surrounding microenvironment of the catalytic metal centers.