Search

Context : Previous theoretical studies have suggested that two-dimensional (2D) MBene materials might display adequate monatomic catalytic activity for the hydrogen evolution reaction (HER). Recently, a study reported the experimental synthesis of a 2D MBene (Mo4/3B2), re-defined as boridene, albeit no effort has been devoted to explore the single-atom catalytic activity for HER of this experimentally synthesized 2D material. Therefore, we herein investigate the single-atom HER performance of the boridene. Interestingly, with Mo defects mixed with single Au and Zn atoms shows excellent hydrogen evolution performance, and the change in the Gibbs free energy ( Δ G H ) value is close to 0 eV, which can even match the performance of Pt-based materials. Through analysis of the charge density difference and density of states, the mechanism affecting the HER performance is explained at the electronic level. This work provides a new direction for the use of the Mo4/3B2 monolayer two-dimensional materials in the field of single-atom catalysis for HER. Methods: This study used the DFT calculations in Vienna ab initio simulation package. The GGA-Perdew-Burke-Ernzerhof functional with DFT-D2 correction is used to describe the exchange–correlation interactions. The projection augmented wave is used with the plane wave cutoff of 500 eV. The convergences of energy and force are 10−5 eV and 0.01 eV/Å, respectively. A vacuum layer with a height of 20 Å is set in the Z direction. For geometry optimization, self-consistent, and DOS calculations, the k-point grids sampled in Brillouin zones are 3 × 3 × 1, 9 × 9 × 1, and 9 × 9 × 1, respectively. The AIMD simulation is performed in the canonical ensemble (NVT), and the temperature was maintained at 300 K by Nosé-Hoover thermostats with a time step of 2.0 fs. [ABSTRACT FROM AUTHOR]

[Display omitted] • The graphitic carbon nitride (g-C 3 N 4) shows unique geometrical characterizes to anchoring metal trimer clusters. • They have excellent catalytic performances for yielding NH 3 products with limiting potential of 0.02–0.50 V involving kinetic barrier of 0.03–0.46 eV. • The establish the relationship between surficial activities and electronic properties. As a cleaner and more energy-efficient alternative, the electrochemical reduction of N 2 to NH 3 under mild conditions has emerged as a promising avenue for environmental protection. However, developing catalysts with both high activity and selectivity has been a challenging task. The advent of atomically dispersed catalysts is revolutionizing the field of catalysis. Drawing inspiration from the successful fabrication of Ru trimer on graphitic carbon nitride (g-C 3 N 4) nanosheets, herein, we adopted a series of trimeric metal clusters anchored on g-C 3 N 4 monolayer (TM 3 @g-C 3 N 4 , TM = 3 d , 4 d and 5 d transition metal atom), as well as utilized the criteria range to describe the stability, activity, energy cost and selectivity of supported trimers for N 2 reduction reaction based on ab initio calculations combined with multi-level screening strategies. Finally, 5 candidate TM 3 @g-C 3 N 4 (TM = Rh, Ru, V, Mo, and Re) exhibits decent catalytic activity with limiting potential ranging of –0.50 – –0.02 V. These spatially confined triatomic metal centers demonstrated proficiency in activating N 2 molecules while exhibiting tunable surficial reactivity through modulation of the metal elements and interfacial electron coupling between trimers and underlying substrates. More importantly, a structure–activity relationship was established, which provides crucial insights for precise design of highly efficient atomically-precise catalysts at an atomic level for hydrogen fuel storage. [ABSTRACT FROM AUTHOR]