Cross-Interface Quasi-Tandem Catalysis Over Amorphous Oxide-Metal Junctions Steers CO₂ Electroreduction Toward C₃...

The selective electroreduction of CO₂ to n-propanol is fundamentally constrained by sluggish C₁─C₂ coupling and the instability of key oxygenated intermediates. Here, we propose a quasi-tandem catalytic strategy enabled by defect-rich amorphous ZrO₂, where the amorphous oxide-metal interfacial environment promotes *CO generation, stabilization of oxygenated C₂ intermediates (*OCCOH), and subsequent C─C coupling toward n-propanol formation. The resulting catalyst, composed of amorphous ZrO₂, Cu, and Ag, delivers a Faradaic efficiency of 23.2% ± 1.6% and a partial current density of 50.6 mA cm^-2 for n-propanol, representing more than 2.5- and 3.5-fold enhancements, respectively, compared to its crystalline ZrO₂ analogue. Density functional theory (DFT) calculations reveal that the amorphous ZrO₂─Cu interface, not only enhances the formation of *COH, but also significantly lowers the energy barriers for *CO-COH coupling and *CO-*OCCOH coupling toward n-propanol generation. These findings establish amorphous oxide-metal interfacial engineering as an effective strategy for quasi-tandem catalysis, enabling cooperative multistep C─C coupling pathways toward selective C₃ electrosynthesis from CO₂.