The electrochem. CO2 reduction reaction (CO2RR) has been recognized as a highly promising technol. approach for realizing carbon capture and utilization.A plethora of metal-oxide (MO) nanostructures have been designed with the merits of unique crystal structures to achieve noticeable advances in the electrochem. CO2RR.However, more efforts are needed to properly elucidate the intricate relationships between their synthesis, structure, and activity.In this perspective, this review centers on: (i) the structural engineering of key factors (e.g., crystal facet, defect, interface, spin, and morphol.), (ii) synthesis strategies governing the development of such structural features, (iii) structure-activity relationships, (iv) catalytic mechanisms of multiple proton/electron transfer steps in conversion of CO2 (e.g., either into C1 (e.g., CO, CH4, and CH3OH) or C2+ products (e.g., C2H4, C2H6, C2H5OH, CH3COOH, and C3H7OH)), and (v) the performance metrics of diverse electrocatalysts (e.g., in terms of Faradaic efficiency, c.d., and stability).The factors controlling the catalyst morphol. and the adsorption/transfer behavior of the key intermediates are also discussed based on in situ/ex-situ techniques combined with d. functional theory.Collectively, this review aims to provide critical insights that can guide the rational design of next-generation MO-based electrocatalysts for efficient and selective CO2 electroreduction