Engineering CO ₂ Reduction Pathways via Alloy‐Support Interactions in Li‐CO ₂ Batteries

Abstract

ABSTRACT Rechargeable Li‐CO 2 batteries (LCBs) hold great promise for dual‐function CO 2 utilization and energy storage, yet their practical application is hindered by the sluggish kinetics of the conventional Li 2 CO 3 pathway, resulting in low discharge voltages (below 2.0 V) and large overpotentials (over 1.0 V). Herein, we propose a strategy of CO 2 reduction pathway engineering via alloy‐support interaction to unlock high‐performance LCBs. We designed a Ru 2 Cu 4 /NC 1000 catalyst, where spectroscopy confirms distinct charge redistribution driven by strong coordination between the Ru 2 Cu 4 alloy and N‐doped support. Theoretical simulations validate that this interaction shifts the Ru and Cu d‐band centers toward the Fermi level and induces interfacial charge redistribution, thus optimizing the electronic structure of the Ru‐Cu active sites for CO 2 reduction. More importantly, this electronic restructuring thermodynamically favors the formation of metastable Li 2 C 2 O 4 over insulating Li 2 CO 3 , thus significantly reducing the activation energy barrier for the rate‐determining step by 0.56 eV. As a result, the cell achieves a minimal overpotential of 0.50 V, an exceptional discharge voltage of 3.23 V, and a high specific capacity of 33 922 mAh g −1 (at 100 mA g −1 ). Our work establishes electron‐state engineering via alloy‐support interactions as a protocol for directing reaction pathways and achieving high‐voltage and durable LCBs.