Efficient Electrochemical Nitrogen Fixation over Isolated Pt Sites

Recently, ambient electrochemical N₂ fixation has gained great attention. However, the commercial Pt-based electrocatalyst hardly shows its potential in this field. Herein, it is found that the isolated Pt sites anchored on WO₃ nanoplates exhibit the optimum electrochemical NH₃ yield rate (342.4 µg h^-1 mg^-1 _Pt ) and Faradaic efficiency (31.1%) in 0.1 m K₂ SO₄ at -0.2 V versus RHE, which are about 11 and 15 times higher than their nanoparticle counterparts, respectively. The mechanistic analysis indicates that N₂ conversion to NH₃ follows an alternating hydrogenation pathway, and positively charged isolated Pt sites with special Pt-3O structure can favorably chemisorb and activate the N₂ . Furthermore, the hydrogen evolution reaction can be greatly suppressed on isolated Pt sites decorated WO₃ nanoplates, which guarantees the efficient going-on of nitrogen reduction reaction.