<p>Efficient production of C₂₊ alcohols from the electrochemical CO₂ reduction reaction (CO₂RR) is of great interest. However, the CO₂RR to C₂₊ alcohols has low selectivity and current density due to competing C₂₊ pathways that produce ethylene (C₂H₄). Here we report a stepwise precipitation and stepwise calcination strategy to create Pr–Cu oxide heterointerfaces (Pr₆O₁₁–Cu-SS) that produces an efficient CO₂RR to C₂₊ alcohols. Pr₆O₁₁–Cu-SS exhibited high productivity and Faradaic efficiency (FE) for C₂₊ alcohols. At −1.08 V versus RHE, the current density and FE of C₂₊ alcohols reached 700 mA cm⁻² and 71.3%, respectively, with the FEs of ethanol and <i>n</i>-propanol reaching 58.6% and 12.7%, respectively, under these conditions. The C₂₊ alcohols/C₂H₄ ratio was as high as 12:1. Experimental and theoretical studies indicated that the performance of the catalyst results from the existence of a Pr⁴⁺/Pr³⁺ structure in Pr₆O₁₁–Cu-SS, which is able to effectively stabilize Cu^δ+/Cu⁰ via a unique Pr–O–Cu linkage and form stable oxide heterointerfaces. The binding strength and binding type of *CO were then altered on the heterointerfaces to form a mixed adsorption configuration, which induces asymmetric carbon–carbon coupling and selective hydrodeoxygenation to promote the generation of C₂₊ alcohols.</p><p></p>