Rational Design of p-Block Metal-Doped Bismuth via Dual Orbital Hybridizations for Ampere-Level CO ₂ -to-Formate Electrosynthesis and Zn–CO ₂ Batteries

Electrochemical conversion of CO2 into formate stands as a compelling pathway toward carbon neutrality, where the attainment of high selectivity under industrial-current-density electrolysis conditions represents a pivotal milestone toward scalable implementation. In this work, dual orbital hybridizations (s–p hybridization of Sn 5s and O 2p orbitals and p–p hybridization of Sn 5p/Bi 6p and O 2p orbitals) are introduced to synergistically regulate charge transfer dynamics between active sites and oxygenated intermediates via integrating p-block metals into bismuth nanosheets. The resulting Sn-doped Bi catalyst (Sn1Bi) achieved a record-breaking partial current density of −2.56 A cm–2 for formate production, sustaining 85.4% Faradaic efficiency even at −3 A cm–2, along with an unprecedented robustness at 2 A for 280 h in a membrane electrode assembly. Ongoing mechanistic studies aim to elucidate that dual orbital hybridizations facilitate CO2 activation and stabilize the critical *OCHO intermediate, thereby optimizing reaction kinetics and formate selectivity. This study advances the rational design of dual p–p and s–p orbital hybridization-engineered electrocatalysts for the selective and efficient valorization of CO2.