[1] WANG Y, JIA K, PAN Q et al. Boron-doped TiO₂ for efficient electrocatalytic N₂ fixation to NH₃ at ambient conditions[J]. ACS Sustain. Chem. Engineer., 117-122(2018).

[2] LI H Y, YANG L, WANG Z X et al. N-heterocyclic carbene as a promising metal-free electrocatalyst with high efficiency for nitrogen reduction to ammonia[J]. J. Energy Chem., 78-86(2020).

[3] LI Q Y, HE L Z, SUN C H et al. Computational study of MoN₂ monolayer as electrochemical catalysts for nitrogen reduction[J]. J. Phys. Chem. C, 27563-27568(2017).

[4] CHOI C, BACK S, KIM N Y et al. Suppression of hydrogen evolution reaction in electrochemical N₂ reduction using single- atom catalysts: a computational guideline[J]. ACS Catal., 7517-7525(2018).

[5] ZHAO W H, ZHANG L F, LUO Q Q et al. Single Mo₁(Cr₁) atom on nitrogen-doped graphene enables highly selective electroreduction of nitrogen into ammonia[J]. ACS Catal., 3419-3425(2019).

[6] WANG S Y, SHI L, BAI X W et al. Highly efficient photo-/ electrocatalytic reduction of nitrogen into ammonia by dual-metal sites[J]. ACS Central Sci., 1762-1771(2020).

[7] MA B Y, PENG Y, Ma D W et al. Boron-doped InSe monolayer as a promising electrocatalyst for nitrogen reduction into ammonia at ambient conditions[J]. Appl. Surf. Sci., 143463(2019).

[8] LING C Y, NIU X H, LI Q et al. Metal-free single atom catalyst for N₂ fixation driven by visible light[J]. J. Am. Chem. Soc., 14161-14168(2018).

[9] LIU X, WANG Z X, ZHAO J et al. Two-dimensional π-conjugated osmium bis(dithiolene) complex (OsC₄S₄) as a promising electrocatalyst for ambient nitrogen reduction to ammonia[J]. Appl. Surf. Sci., 833-839(2019).

[10] JI S, WANG Z X, ZHAO J X. A boron-interstitial doped C₂N layer as a metal-free electrocatalyst for N₂ fixation: a computational study[J]. J. Mater. Chem. A, 2392-2399(2019).

[11] ZHANG X, CHEN A, ZHANG Z H et al. Double-atom catalysts: transition metal dimer-anchored C₂N monolayers as N₂ fixation electrocatalysts[J]. J. Mater. Chem. A, 18599-18604(2018).

[12] LI F F, CHEN L, LIU H M et al. Enhanced N₂-fixation by engineering the edges of two-dimensional transition-metal disulfides[J]. J. Phys. Chem. C, 22221-22227(2019).

[13] QIN G Q, CUI Q Y, DU A J et al. Transition metal diborides: a new type of high-performance electrocatalysts for nitrogen reduction[J]. ChemCatChem, 2624-2633(2019).

[14] ZHU H R, HU Y L, WEI S H et al. Single-metal atom anchored on boron monolayer (β₁₂) as an electrocatalyst for nitrogen reduction into ammonia at ambient conditions: a first-principles study[J]. J. Phys. Chem. C, 4274-4281(2019).

[15] WANG S M, ZHANG L, QIN Y et al. Co, N-codoped graphene as efficient electrocatalyst for hydrogen evolution reaction: insight into the active centre[J]. J. Power Sources, 260-268(2017).

[16] YANG Y L, LIU J D, WEI Z X et al. Transition metal-dinitrogen complex embedded graphene for nitrogen reduction reaction[J]. ChemCatChem, 2821-2827(2019).

[17] RIYAZ M, GOEL N. Single-atom catalysis using chromium embedded in divacant graphene for conversion of dinitrogen to ammonia[J]. ChemPhysChem, 1954-1959(2019).

[18] SUN C N, WANG Z L, LANG X Y et al. Synergistic effect of active sites of double-atom catalysts for nitrogen reduction reaction[J]. ChemSusChem, 4593-4600(2021).

[19] ZHENG X N, YAO Y, WANG Y et al. Tuning the electronic structure of transition metals embedded in nitrogen-doped graphene for electrocatalytic nitrogen reduction: a first-principles study[J]. Nanoscale, 9696-9707(2020).

[20] ZHOU Y, SONG E H, CHEN W et al. Dual-metal interbonding as the chemical facilitator for single-atom dispersions[J]. Adv. Mater., e2003484(2020).

[21] DELLY B. An all-electron numerical method for solving the local density functional for polyatomic molecules[J]. J. Chem. Phys., 508-517(1990).

[22] DELLY B. From molecules to solids with the DMol³ approach[J]. J. Chem. Phys., 7756-7764(2000).

[23] OERDEW J P, BURKE K, ERNZERHOF M. Generalized gradient approximation made simple[J]. Phys. Rev. Lett., 3865-3868(1996).

[24] DELLY B. Hardness conserving semilocal pseudopotentials[J]. Phys. Rev. B, 155125(2002).

[25] TODOROVA T, DELLY B. Wetting of paracetamol surfaces studied by DMol³-COSMO calculations[J]. Mol. Simulat., 1013-1017(2008).

[26] WEI Z X, ZHANG Y F, WANG S Y et al. Fe-doped phosphorene for the nitrogen reduction reaction[J]. J. Mater. Chem. A, 13790-13796.

[27] SHI L, LI Q, LING C Y et al. Metal-free electrocatalyst for reducing nitrogen to ammonia using a Lewis acid pair[J]. J. Mater. Chem. A, 4865-4871(2019).

[28] JIANG C H, ZHOU R Q, PENG Z H et al. An atomically thin layer of Ru/MoS₂ heterostructure: structural, electronic, and magnetic properties[J]. Phys. Chem. Chem. Phys., 32528-32533(2016).

[29] YU X M, HAN P, WEI Z X et al. Boron-doped graphene for electrocatalytic N₂ reduction[J]. Joule, 1610-1622(2018).

[30] NORSKOV J K, ROSSMEISL J, LOGADOTTIR A et al. Origin of the overpotential for oxygen reduction at a fuel-cell cathode[J]. J. Phys. Chem. B, 17886-17892(2004).

[31] YANG L, FENG S, ZHU W. Tuning nitrate electroreduction activity via an equilibrium adsorption strategy: a computational study[J]. J Phys. Chem. Lett., 1726-1733(2022).

[32] LIM D H, WILCOX J. Mechanisms of the oxygen reduction reaction on defective graphene-supported Pt nanoparticles from first-principles[J]. J. Phys. Chem. C, 3653-3660(2012).

[33] YIN J, FANG Q H, LI Y X et al. Ni-C-N nanosheets as catalyst for hydrogen evolution reaction[J]. J. Am. Chem. Soc., 14546-14549(2016).

[34] LIANG H W, BRULLER S, DONG R H et al. Molecular metal-N_x centres in porous carbon for electrocatalytic hydrogen evolution[J]. Nat. Commun., 7992(2015).

[35] LING C Y, OUYANG Y X, LI Q et al. A general two-step strategy-based high-throughput screening of single atom catalysts for nitrogen fixation[J]. Small Methods, 1-8(2019).

[36] QI J M, GAO L Y, WEI F F et al. Design of a high-performance electrocatalyst for N₂ conversion to NH₃ by trapping single metal atoms on stepped CeO₂[J]. ACS Appl. Mater. Interfaces, 47525-47534(2019).

[37] SKULASON E, BLIFAARD T, GUDMUNDSDOTTIR S. A theoretical evaluation of possible transition metal electro- catalysts for N₂ reduction[J]. Phys. Chem. Chem. Phys., 1235-1245(2012).

[38] CHOI W I, WOOD B C, SCHWEGLER E et al. Combinatorial search for high-activity hydrogen catalysts based on transition- metal-embedded graphitic carbons[J]. Adv. Energy Mater., 1501423(2015).

[39] LIU C W, LI Q Y, ZHANG J et al. Conversion of dinitrogen to ammonia on Ru atoms supported on boron sheets: a DFT study[J]. J. Mater. Chem. A, 4771-4776(2019).

[40] LI X F, LI Q K, CHENG J et al. Conversion of dinitrogen to ammonia by FeN₃-embedded graphene[J]. J. Am. Chem. Soc., 8706-8709(2016).

[41] QIU W B, XIE X Y, QIU J D et al. High-performance artificial nitrogen fixation at ambient conditions using a metal-free electrocatalyst[J]. Nat. Commun., 3485(2018).

[42] GUO Y, GU J X, ZHANG R et al. Molecular crowding effect in aqueous electrolytes to suppress hydrogen reduction reaction and enhance electrochemical nitrogen reduction[J]. Adv. Energy Mater., 2101699(2021).

[43] GUO Y X, YAO Z Y, TIMMER B J J et al. Boosting nitrogen reduction reaction by bio-inspired FeMoS containing hybrid electrocatalyst over a wide pH range[J]. Nano Energy, 62, 282-288(2019).

[44] WANG X, FENG Z, XIAO B et al. Polyoxometalate-based metal-organic framework-derived bimetallic hybrid materials for upgraded electrochemical reduction of nitrogen[J]. Green Chem., 6157-6169(2020).

[45] ZHAO J X, CHEN Z F. Single Mo atom supported on defective boron nitride monolayer as an efficient electrocatalyst for nitrogen fixation: a computational study[J]. J. Am. Chem. Soc., 12480-12487(2017).

[46] LING C Y, BAI X W, OUYANG Y X et al. Single molybdenum atom anchored on N-doped carbon as a promising electrocatalyst for nitrogen reduction into ammonia at ambient conditions[J]. J. Phys. Chem. C, 16842-16847(2018).

[47] WU Y B, HE C, ZHANG W X. “Capture-backdonation-recapture” mechanism for promoting N₂ reduction by heteronuclear metal- free double-atom catalysts[J]. J Am. Chem. Soc., 9344-9353(2022).