<p>Electrochemical CO₂ reduction reaction (CO₂RR), driven by renewable energy, offers a promising solution to mitigate increasing CO₂ emissions and establish a carbon–neutral cycle. Copper is a highly selective and active catalyst for CO₂RR but suffers from structural reconstruction challenges. Hybrid organic/inorganic materials address these issues by offering customizable compositions and interfaces. Recently, Buonsanti’s team developed hybrid Cu@AlOx nanocrystals with tunable alumina shells via a colloidal atomic layer deposition approach, achieving stable and selective methane production during CO₂RR. Mechanistic studies reveal that the alumina shell stabilizes oxidized copper species through Cu²⁺–O–Al motifs coordinated with AlO₄ Lewis acid sites, reducing copper dissolution and structural reconstruction. This study provides key insights into the mechanism underlying stabilization, highlighting the critical role of Lewis acidity in preserving the structural integrity of the catalyst. This highlight review aims to inspire the development of other high-performance and stable catalysts through colloidal atomic layer deposition strategies.</p>