Hierarchical Modulation in Cu‐Aerogel Enables Breakthrough CO ₂ Electroreduction for Combating Stability‐Efficiency‐Selectivity Tradeoff

Design of electrocatalyst combining low overpotential, high selectivity and stability for combating the stability-efficiency-selectivity tradeoff in CO₂ electroreduction remains a crucial challenge. Herein, a hierarchical modulation strategy is proposed for the precise assembly of Boron (B) and Tin (Sn), resulting in novel copper (Cu)-aerogel (BSnCu3) structures with both structural and functional hierarchies for advanced CO₂ electroreduction. Superficial assembled Tin creates Cu⁰ protective layer for high stability, the body assembled Boron improves the binding affinity to intermediates and shifts Cu d-band upward for enhanced charge transfer. BSnCu3 achieves exceptional performance, including an ethanol selectivity of 93.2%, a Faradaic efficiency (FE) of 90.3%, and an ultralow overpotential of 0.12 V, alongside remarkable stability. Leveraging the synergistic effects of regionally assembled Boron/Tin and the efficient charge/mass transfer of the 3D nanowire network, BSnCu3 attains a record-breaking tradeoff index of 2.74, surpassing all reported values. This work presents an inspiring strategy and sets a new benchmark for advanced electrocatalyst design.