The PdHx metallene with vacancies for synergistically enhancing electrocatalytic N2 fixation

In this work, the ultrathin (0.9 nm) of interstitial metallene with controlled vacancies are successfully prepared for the first time. The interstitial V Pd -PdH 0.41 metallene displays a unique nitrogen reduction (NRR) activity in Li 2 SO 4 solution. • Ultrathin interstitial metallene with vacancies are obtained for the first time. • TOF of V Pd -PdH 0.41 is 14.97 times than Pd NSs without vacancies. • This catalyst has great stability during the continuous test for 100 h. • In situ Raman/ATR-SEIRAS/DFT display the synergy mechanism for NRR. It is of great significance to controlled synthesis of high activity, selectivity and durable electrocatalysts. In this work, for the first time, the ultrathin (0.9 nm) of interstitial metallene with controlled vacancies and lattice hydrogen atoms are successfully gained. With the optimal lattice hydrogen atoms and composition, the interstitial V Pd -PdH 0.41 metallene exhibits the great nitrogen reduction (NRR) activity in Li 2 SO 4 solution, among interstitial PdH x with different extent of vacancies, interstitial PdH 0.41 without vacancies and Pd nansheets. The density functional theory (DFT), in situ Raman and Attenuated total reflection surface-enhanced infrared absorption spectrum (ATR-SEIRAS) tests further display that the V Pd on the interstitial V Pd -PdH 0.41 metallene can urges the adsorption and arousal of N 2 , while lattice hydrogen atoms as active hydrogen source to follow an association mechanism rather than a dissociation mechanism, showing nice NRR performance at low overpotential.