Synergistic electrode design for efficient CO₂ electrolysis to multicarbon products at elevated temperatures

Electrocatalytic CO₂ reduction reaction (CO₂RR) technology holds significant industrial potential. However, when faced with elevated-temperature environments caused by industrial-scale operations, the fundamental understanding of temperature-dependent CO₂RR behavior in flow cells remains elusive. This study points out that elevated-temperature operation (>333 K) presents both challenges and opportunities for multi-carbon (C₂₊) production. While elevated temperature enhances reaction kinetics and reduces thermodynamic energy barriers, it simultaneously induces reconstruction of Cu-based catalyst, accelerates gas diffusion electrode flooding, and promotes *CO desorption together with hydrogen evolution reaction, collectively suppressing C₂₊ product formation and compromising long-term reactor stability. Through rational design of hydrophobic-enhanced Pd-Cu₂O/polytetrafluoroethylene (PTFE)/Ag tandem electrodes, we overcome these challenges. Leveraging thermal reduced C-C coupling barriers, the optimized electrode achieves >70% Faradaic efficiency of C₂₊ across industrially relevant current densities (200-1000 mA cm^-2) at 348 K. This strategy converts elevated temperature adversity into a kinetic and thermodynamic advantage, boosting C₂₊ cathodic energy efficiency by 1.3 times compared to ambient operation, establishing a promising paradigm for industrially viable CO₂ electrolysis.