Vacancy Engineering of Iron‐Doped W<sub>18</sub>O<sub>49</sub> Nanoreactors for Low‐Barrier Electrochemical Nitrogen Reduction
Yueyu Tong, Haipeng Guo, Daolan Liu, Xiao Yan, Panpan Su, Ji Liang, Si Zhou, Jian Liu, Gao Qing Lu, Shi Xue Dou
Abstract
Abstract The electrochemical nitrogen reduction reaction (NRR) is a promising energy‐efficient and low‐emission alternative to the traditional Haber–Bosch process. Usually, the competing hydrogen evolution reaction (HER) and the reaction barrier of ambient electrochemical NRR are significant challenges, making a simultaneous high NH 3 formation rate and high Faradic efficiency (FE) difficult. To give effective NRR electrocatalysis and suppressed HER, the surface atomic structure of W 18 O 49 , which has exposed active W sites and weak binding for H 2 , is doped with Fe. A high NH 3 formation rate of 24.7 μg h −1 mg cat −1 and a high FE of 20.0 % are achieved at an overpotential of only −0.15 V versus the reversible hydrogen electrode. Ab initio calculations reveal an intercalation‐type doping of Fe atoms in the tunnels of the W 18 O 49 crystal structure, which increases the oxygen vacancies and exposes more W active sites, optimizes the nitrogen adsorption energy, and facilitates the electrocatalytic NRR.