(TM-O<sub>4</sub>)<sub>3</sub>@h-B<sub>12</sub>N<sub>12</sub> for Hydrogen Evolution Reaction and Achieving Highly Efficient Single-Functional Oxygen Evolution Reaction Catalysis via Axial Ligand Modifi

在碳中和战略推动下，开发高效稳定的非贵金属催化剂已成为清洁能源领域的重要研究方向。通过构建多孔h-BN (B12N12)基底并引入过渡金属(TM)-O4配位结构，成功构建单原子催化剂。密度泛函理论计算表明：(Os-O4)3@h-B12N12在氢析出反应(HER)中表现出优异活性(ηHER = 0.09 V)，展现出替代贵金属催化剂的潜力。值得注意的是，该体系在析氧反应(OER)和氧还原反应(ORR)中的催化性能未达预期。针对此瓶颈，我们创新性地对(Rh-O4)3@h-B12N12体系引入轴向Cl配体进行结构修饰。理论计算结果显示，Cl配体的引入显著改变了Rh原子在费米能级附近的电子分布状态，优化了金属中心与O4配体间的协同作用。这种电子结构的调整有效改善了催化剂对含氧中间体的吸附强度，使得OER理论过电位从初始体系的0.814 V显著降低至0.395 V。本研究通过配位工程策略实现了h-BN基催化剂的选择性性能调控，其中(Os-O4)3@h-B12N12在HER中的突出表现以及Cl-(Rh-O4)3@h-B12N12在OER中的活性提升，为设计非贵金属双功能催化剂提供了新的理论视角。特别是轴向配体修饰策略的成功实施，为二维材料催化活性位点的精准调控开辟了创新路径。Under the impetus of the carbon neutrality strategy, the development of efficient and stable non-precious metal catalysts has become an important research direction in the field of clean energy. The single-atom catalyst was successfully constructed by constructing a porous h-BN(B12N12) substrate and introducing the transition metal (TM)-O4 coordination structure. Density functional theory calculations show that: (Os-O4)3@h-B12N12 exhibits excellent activity (ηHER = 0.09 V) in the hydrogen evolution reaction (HER), demonstrating potential as an alternative to noble metal catalysts. It is worth noting that the catalytic performance of this system in the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) did not meet expectations. To address this bottleneck, we innovatively introduced axial Cl ligands to the (Rh-O4)3@h-B12N12 system for structural modification. Theoretical calculation results show that the introduction of the Cl ligand significantly changes the electron distribution state of the Rh atom near the Fermi level and optimizes the synergy between the metal center and the O4 ligand. This adjustment of the electronic structure effectively improved the adsorption strength of the catalyst for oxygen-containing intermediates, significantly reducing the theoretical overpotential of OER from 0.814 V in the initial system to 0.395 V. In this study, the selective performance control of H-BN-based catalysts was achieved through coordination engineering strategy. Among them, the outstanding performance of (Os-O4)3@h-B12N12 in HER and the enhanced activity of Cl-(Rh-O4)3@h-B12N12 in OER provide a new theoretical perspective for the design of non-noble metal bifunctional catalysts. In particular, the successful implementation of the axial ligand modification strategy has opened up an innovative path for the precise regulation of catalytic active sites in two-dimensional materials.