The development of high‐performance catalysts with high activity, selectivity, and stability are essential for the practical applications of H2O2 electrosynthesis technology, but it is still formidably challenging. It is reported that the low‐coordinated structure of Pd sites in amorphous PdSe2 nanoparticles (a‐PdSe2 NPs) can significantly boost the electrocatalytic synthesis of H2O2. Detailed investigations and theoretical calculations reveal that the disordered arrangement of Pd atoms in a‐PdSe2 NPs can promote the activity, while the Pd sites with low‐coordinated environment can optimize the adsorption toward oxygenated intermediate and suppress the cleavage of O–O bond, leading to a significant enhancement in both the H2O2 selectivity and productivity. Impressively, a‐PdSe2 NPs/C exhibits high H2O2 selectivity over 90% in different pH electrolytes. H2O2 productivities with ≈3245.7, 1725.5, and 2242.1 mmol gPd−1 h−1 in 0.1 m KOH, 0.1 m HClO4, and 0.1 m Na2SO4 can be achieved, respectively, in an H‐cell electrolyzer, being a pH‐universal catalyst for H2O2 electrochemical synthesis. Furthermore, the produced H2O2 can reach 1081.8 ppm in a three‐phase flow cell reactor after 2 h enrichment in 0.1 m Na2SO4, showing the great potential of a‐PdSe2 NPs/C for practical H2O2 electrosynthesis.

Herein, the catalytic properties and reaction mechanisms of the 3d, 4d, and 5d transition metals embedded in 2D rectangular tetracyanoquinodimethane (TM-rTCNQ) monolayers as single-atom catalysts (SACs) for the electrocatalytic N 2 reduction reaction (NRR) were systematically investigated, using first-principles calculations. A series of high-throughput screenings were carried out on 30 TM-rTCNQ monolayers, and all possible NRR pathways were explored. Three TM-rTCNQ (TM = Mo, Tc, and W) SACs were selected as promising new NRR catalyst candidates because of their high structural stability and good catalytic performance (low onset potential and high selectivity). Our results show that the Mo-rTCNQ monolayer can catalyze NRR through a distal mechanism with an onset potential of −0.48 V. Surprisingly, the NH 3 desorption energy on the Mo-rTCNQ monolayer is only 0.29 eV, the lowest one reported in the literature so far, which makes the Mo-rTCNQ monolayer a good NRR catalyst candidate. In-depth research studies on the structures of N 2 −TM-rTCNQ (TM = Mo, Tc, and W) found that strong adsorption and activation performance of TM-rTCNQ for N 2 may be due to the strong charge transfer and orbital hybridization between the TM-rTCNQ catalyst and the N 2 molecules. Our work provides new ideas for achieving N 2 fixation under environmental conditions.