The electrochemical CO2 reduction reaction (CO2RR) holds the promise to revolutionize the chemical industry by producing value-added chemicals and fuels from CO2 and water while storing renewable energy. However, catalyst design still remains one of the major hurdles in the field. This Perspective discusses the current and future contribution of well-defined nanocatalysts to improving the CO2RR selectivity towards C2 products, particularly ethylene and ethanol. In this regard, the shape and size selectivity dependence of single metal copper nanocrystals is briefly reviewed and linked to single crystal studies. Representative studies on Cu-based bimetallic nanocrystals are discussed to highlight the importance of composition and distribution of the metals for selectivity. Finally, a vision on design strategies of shape and composition for the next generation of CO2RR nanocatalysts is proposed.