Defect-Induced Ce-Doped Bi2WO6 for Efficient Electrocatalytic N2 Reduction

Electrochemical nitrogen reduction reaction (NRR) is a promising method for synthesizing ammonia (NH 3 ). However, due to the extremely strong N≡N bond and the competing hydrogen evolution reaction (HER), the electrochemical NRR process remains a great challenge in achieving a high NH 3 yielding rate and a high Faradaic efficiency (FE). Recently, either Bi-based or W-based catalysts have been used in N 2 fixation due to lower HER activity. To further promote N 2 activation, we develop a simple protocol to introduce and adjust the crystal defects in the host lattice of Bi 2 WO 6 nanoflowers via adjusting the amount of Ce dopant (denoted as x Ce-Bi 2 WO 6, where x represents the designed mole percentage of Ce). At −0.20 V versus the reversible hydrogen electrode (RHE), 10%Ce-Bi 2 WO 6 manifests a high NH 3 yielding rate (22.5 μg h –1 mg –1 cat. ), a high FE (15.9%), and excellent electrochemical and structure durability. Its performance is better than most previously reported Bi-based and W-based electrocatalysts for NRR in aqueous solutions. According to density functional theory (DFT) calculations, the introduction of crystal defects into Bi 2 WO 6 can strengthen the adsorption and activation of N 2, thus leading to a significant increase in NRR activity.