Abstract
Fixation nitrogen using renewable energy has attracted much attention recently. However, the performance is limited by the competing hydrogen evolution reaction (HER) and the difficulty in activating N-2. Here, an attractive strategy was proposed to enhance the electrochemical nitrogen reduction reaction (NRR) activity by introducing Pd into the HKUST-1 framework. After thermal treatment, the obtained Pd/HKUST-1 (250 & DEG;C) catalyst exhibited an ammonia production rate of 42.0 mg/g(cat) . h at -0.4 V vs. RHE with Faradaic efficiency of 4.6 %. The ammonia production reached as high as 415 mg/g(cat) in a 10-hours stability test. With the assistance of density functional theory (DFT) calculations, the incorporated Pd was revealed to have the unique property to react with adsorbed H (H-ad) atom from HER and form alpha-PdH species. Compared with other metals such as Ag, Au, and Pt, the in situ formed alpha-PdH species could reduce the energy barrier of the rate-limiting *N2H step, resulting in an enhanced NRR activity.