Defect-Induced Ce-Doped Bi2wo6 For Efficient Electrocatalytic N-2 Reduction

Electrochemical nitrogen reduction reaction (NRR) is a promising method for synthesizing ammonia (NH3). However, due to the extremely strong N equivalent to N bond and the competing hydrogen evolution reaction (HER), the electrochemical NRR process remains a great challenge in achieving a high NH3 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 Bi2WO6 nanoflowers via adjusting the amount of Ce dopant (denoted as xCe-Bi2WO6, where x represents the designed mole percentage of Ce). At - 0.20 V versus the reversible hydrogen electrode (RHE), 10%Ce-Bi2WO6 manifests a high NH3 yielding rate (22.5 mu g h(-1) mg(cat)(-1).), 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 Bi2WO6 can strengthen the adsorption and activation of N-2, thus leading to a significant increase in NRR activity.