Electrochemical carbon dioxide reduction (CO2R) can provide a sustainable pathway towards various chemicals and fuels when it is powered by renewable energy sources. In this reaction, an evolution of hydrogen which is competing reaction during CO2R should be minimized. Another challenge is to maximize multicarbon products (C2+ products) over products containing only one carbon atom (C1 products), because C2+ products have higher economic values than C1 products and they can be readily used as raw materials for conventional thermo-catalytic processes as well. Among various catalysts for CO2R, Copper (Cu)-based materials are the only known catalytic materials for CO2R with high activity and selectivity toward C2+products which are strong function of microenvironments near the catalyst. In this regard, the impact of microenvironments near Cu catalyst will be discussed and how to engineer them with coatings of ionomers which are ion conductive polymers will be introduced.