A High-Throughput Screening toward Efficient Nitrogen Fixation: Transition Metal Single-Atom Catalysts Anchored on an Emerging π–π Conjugated Graphitic Carbon Nitride (g-C₁₀N₃) Substrate with Dirac Dispersion

Abstract

TM-N x is becoming a comforting catalytic center for sustainable and green ammonia synthesis under ambient conditions, resulting in increasing interest in single-atom catalysts (SACs) for the electrochemical nitrogen reduction reaction (NRR). However, given the poor activity and unsatisfactory selectivity of existing catalysts, it remains a long-standing challenge to design efficient catalysts for nitrogen fixation. Currently, the two-dimensional (2D) graphitic carbon-nitride substrate provides abundant and evenly distributed holes for stably supporting transition-metal atoms, which presents a fascinating prospect for overcoming this challenge and promoting single-atom NRR. An emerging holey graphitic carbon-nitride skeleton with a C10N3 stoichiometric ratio (g-C10N3) from a supercell of graphene is constructed, which provides outstanding electric conductivity for achieving high-efficiency NRR due to the Dirac band dispersion. Herein, a high-throughput first-principles calculation is carried out to evaluate the feasibility of π–d conjugated SACs resulting from a single TM atom anchored on g-C10N3 (TM = Sc–Au) for NRR. We find that W metal embedded in g-C10N3 (W@g-C10N3) can compromise the ability to adsorb the key target reaction species (N2H and NH2), hence acquiring an optimal NRR behavior among 27 TM-candidates. Our calculations demonstrate that W@g-C10N3 shows a well-suppressed HER ability and, impressively, a low energy cost of −0.46 V. Additionally, all-around descriptors are proposed to uncover the fundamental mechanism of NRR activity, among which a 3D volcano plot (limiting potential, screening strategy, and electron origin) uncovers the NRR activity trend, achieving a quick and high-efficiency prescreening for numerous candidates. Overall, the strategy of the structure- and activity-based TM-N x -containing unit design will offer useful insight for further theoretical and experimental attempts.

Theoretical prediction of emerging high-performance trifunctional ORR/OER/HER single-atom catalysts: transition metals anchored into π–π conjugated graphitic carbon nitride (g-C10N3)

“…1a, which possesses an intrinsic central cavity to stably anchor one TM and further exists in the form of SACs, realized by TM@g-C 10 N 3 . 18 We choose VIII group elements, including 3d TM (Fe, Co, and Ni), 4d TM (Ru, Rh, and Pd), and 5d TM (Os, Ir, and Pt) to anchor into g-C 10 N 3 to build SACs. We have considered two N-coordination environments, one where the TM is surrounded by two N atoms (red circle represents site I) and the other where the TM is surrounded by three N atoms (the green circle represents site II), as plotted in Fig.…”

“…Encouragingly, Zhang et al have demonstrated that TM anchored into g-C 10 N 3 exhibits good stability, excellent conductivity, and high NRR catalytic activity. 18 Otherwise, a report shows that Re can be stably anchored into g-C 10 N 3 , offering a promising strategy for formation of SACs. 19 Therefore, based on these properties of g-C 10 N 3 , we predict that g-C 10 N 3 is likely to be a promising substrate to anchor TM atoms for the ORR/OER/HER.…”

High‐Throughput Calculations for Screening d‐ and p‐Block Single‐Atom Catalysts toward Li2S/Na2S Decomposition Guided by Facile Descriptor beyond Brønsted–Evans–Polanyi Relationship

“…Overall, we believe that this strategy can also be applied to screen SACs for Li─S and Na─S batteries supported by C x N y systems containing cavities (similar to g-C 3 N 4 ), such as C 2 N, [38] C 3 N 3 , [39] and C 10 N 3 . [40] For the screened MM@g-C 3 N 4 (including seven TM@g-C 3 N 4 and three MM@g-C 3 N 4 ), their ability to inhibit the shuttle effect was investigated. The anchoring capacity of the reaction intermediates on seven TM@g-C 3 N 4 was evaluated based on the adsorption energy, as shown in Figure 7a.…”

d- and p-Block single-atom catalysts supported by BN nanocages toward electrochemical reactions of N2 and O2

“…DLP = LP NRR À LP HER . 77,79 A positive deviation of DLP with respect to À0.5 V demonstrates a favorable NRR selectivity. The more positive the DLP value is, the higher the NRR selectivity of the TM@BNNCs.…”