Two-dimensional transition metal borides (MBenes), particularly TiB, hold promise as electrocatalysts for CO₂-related reactions. However, their bifunctional catalytic performance for reversible Li₂CO₃ conversion in Li–CO₂ batteries remains inferior to that of Ru-based catalysts. We addressed this issue by introducing tensile strain and doping late transition metal atoms (Mn, Fe, Co, Ni, Cu) into the basal plane of a TiB MBene/graphene heterostructure. Spin-polarized density functional theory (DFT) calculations revealed that the Cu-doped TiB/graphene catalyst (Cu/Ti₁₇B₁₈/G) exhibits an ultralow CO₂ reduction and evolution overpotential of 0.66 V, enhancing Li₂CO₃ nucleation and reversible conversion with carbon products. This improvement is attributed to weakened adsorption of O-containing intermediates on the Cu-doped surface, facilitated by the down-shifted d-band center and increased antibonding state occupancy. Consequently, Cu/Ti₁₇B₁₈/G emerges as a promising bifunctional electrocatalyst for Li–CO₂ batteries, outperforming pristine TiB/G and other reported catalysts. Furthermore, its bifunctional activity can be further improved by applying x-direction tensile strain. Molecular dynamics simulations combined with explicit solvent models further confirmed the catalytic durability and stability of Cu/Ti₁₇B₁₈/G in solution. This work provides valuable atomic-scale insights for exploring advanced Li–CO₂ battery catalysts.

中文翻译：

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利用用于 Li-CO2 电池的 Cu 掺杂 TiB MBene/石墨烯增强 Li2CO3 可逆转换


二维过渡金属硼化物（MBenes），特别是TiB，有望作为CO ₂相关反应的电催化剂。然而，它们在Li-CO ₂电池中可逆Li ₂ CO ₃转化的双功能催化性能仍然不如Ru基催化剂。我们通过引入拉伸应变并将后过渡金属原子（Mn、Fe、Co、Ni、Cu）掺杂到 TiB MBene/石墨烯异质结构的基面中解决了这个问题。自旋极化密度泛函理论（DFT）计算表明，Cu掺杂TiB/石墨烯催化剂（Cu/Ti ₁₇ B ₁₈ /G）表现出0.66 V的超低CO ₂还原和演化超电势，增强了Li ₂ CO ₃成核和与碳产品的可逆转化。这种改进归因于含氧中间体在铜掺杂表面上的吸附减弱，这是由于d带中心下移和反键态占据增加所促进的。因此，Cu/Ti ₁₇ B ₁₈ /G 成为一种有前途的 Li-CO ₂电池双功能电催化剂，其性能优于原始 TiB/G 和其他报道的催化剂。此外，通过施加x方向拉伸应变可以进一步提高其双功能活性。 分子动力学模拟结合显式溶剂模型进一步证实了Cu/Ti ₁₇ B ₁₈ /G在溶液中的催化耐久性和稳定性。这项工作为探索先进的 Li-CO ₂电池催化剂提供了宝贵的原子尺度见解。