There has been significant progress in the electrochemical reduction of CO2 since Hori's 1985 discovery of hydrocarbon products at Cu electrodes. Since then, several advances have led to ethanol, ethylene, and acetate production at relatively high current densities and Faradaic efficiencies. The level of progress towards industrial-scale CO2 electroreduction within the last decade has been extraordinary; however, several barriers to commercialization remain. Foremost among these are the limited availability and relatively high cost of electricity from renewables or nuclear sources. Relative to the chlor-alkali process, which produces over 80 million metric tons per year via brine electrolysis, the specific energy requirements for C2 products are much higher. For example, ethylene and ethanol require approximately 30 kWh kg−1 and acetic acid or acetate requires approximately 15 kWh kg−1. Even with optimistic predictions of future solar and wind energy costs near $0.03 per kWh, the electrical demand alone results in specific cost that are 2 to 3 times the cost of conventional methods. Further, other requirements such as separation energy and capital costs, can result in added expenses that are on par with the cost of electrolysis alone. In terms of selectivity and carbon efficiency, several works have made progress in terms of the reaction mechanisms and transport of reactants and products. In this regard, we have proposed several reaction mechanisms for ethanol and ethylene that progress through a ketene to acetyl species and a related path for acetate. Our research on reaction mechanisms reveals that Cu active site electronic properties play a role in product selectivity. Cu-P0.065 (Cuδ+ = 0.13) was shown to provide 70% Faradaic efficiency for ethylene in weakly acidic conditions, Cu-Sn0.03 (Cuδ+ = 0.27) electrocatalysts produce 48% FE to ethanol at 350 mA cm−2 in alkaline conditions, and Cu2Se (Cuδ+ = 0.47) can provide over to 40% FE to acetate. Feed composition and pH strongly influence products: pure CO feeds favor acetate (60% FE), while CO2 co-feeding enhances ethylene selectivity to 42% FE. These electrocatalysts maintain stability over 250 hours with minimal degradation; however, several selectivity and efficiency challenges remain. Our research has revealed that water management and salt precipitation remain as key challenges in CO2 reduction via zero-gap membrane electrode assemblies (MEAs), with performance limited by membrane-specific critical current densities. Previous work showed that CO2 electroreduction to C2 products requires water from the anode, and each bicarbonate/carbonate ion co-transports 6-10 water molecules via electroosmotic drag, establishing membrane stability limits based on water transport. Critical current densities for stable operation were estimated near 180 mA·cm⁻² for Sustainion X37-50RT, 45 mA·cm⁻² for PiperION 60, and 30 mA·cm⁻² for Fumasep FAA-3-50. Operating below these thresholds enables remarkable stability - demonstrated by a 1,000-hour continuous operation at a current density of 135 mA·cm⁻². Durability challenges also extend to both electrocatalysts and membranes. Our studies showed copper-based electrocatalysts experience a 19% reduction in electrochemical surface area increasing overpotential by over 400 mV at 150 mA·cm⁻². Anion exchange membranes face hydroxide attack: Sustainion® X37-50 experiences imidazolium cleavage, PiperION undergoes Hoffman elimination, and FAA-3-50 shows nucleophilic substitution. These result in decreased conductivity and significant mechanical integrity losses. The loss of ionic conductivity and mechanical integrity is evidenced by increasing cell potentials and physical membrane failures. In terms of techno-economics, product separation adds significant challenges. PSA-based separations for ethylene struggle with light ends (hydrogen and carbon monoxide) are particularly problematic at low pressures. This adds substantial cost to ethylene separation and impacts ethanol and acetic acid economics. Likewise, ethanol separation from water requires significant energy at low concentrations, with another challenge being ethanol oxidation at the anode. Further, acetate production can be costly because it requires equimolar base consumption and there are challenges in separating acetic acid or acetate from the electrolyte and other MEA products. These are primarily engineering challenges and there are several potential solutions that could enable commercializing CO2 reduction to C2 products.