Electrochemical CO2 reduction reaction (CO2RR) holds promise for storing and utilizing renewable electricity, contributing to carbon neutralization efforts. However, significant challenges persist in transitioning CO2RR devices to industrial applications. This research addresses key hurdles, focusing on enhancing carbon utilization, versatility, and controllability of CO2 electrolysis through device engineering and local environment adjustments. Specifically, our investigations encompass: CO2 recovery using solid electrolytes, investigating selectivity differences between CO2 and CO within local environments, and designing novel covalent framework-based solid electrolytes. The findings from our investigations not only provide insights into fundamental aspects of CO2 reduction but also offer practical pathways for realizing more efficient and sustainable CO2 utilization technologies.