Insights from\nTechno-Economic Analysis Can Guide the\nDesign of Low-Temperature CO<sub>2</sub> Electrolyzers toward Industrial\nScaleup

The field of CO<sub>2</sub> reduction has identified\nseveral challenges\nthat must be overcome to realize its immense potential to simultaneously\nclose the carbon cycle, replace fossil-based chemical feedstocks,\nand store renewable electricity. However, frequently cited research\ntargets were set without quantitatively analyzing their impact on\neconomic viability. Through a physics-informed techno-economic assessment,\nwe offer guidance on top priorities for CO<sub>2</sub> reduction.\nAlthough separations dominate capital cost, increasing single-pass\nconversion is unnecessary because it leads to selectivity loss in\ncurrent membrane electrode assemblies. Decoupling selectivity and\nsingle-pass conversion by moving away from a plug flow reactor design\nwould reduce the base case levelized cost from $1.22/kg<sub>CO</sub> to $0.97/kg<sub>CO</sub>, as impactful as eliminating CO<sub>2</sub>R overpotential. Operating at high current densities (>500 mA/cm<sup>2</sup>) is undesirable unless cell voltages can be lowered. We confirm\nthat levelized product cost is dominated by the cost of electricity\nto drive electrolysis. Although wholesale wind and solar electricity\nare cheaper than retail electricity, their capacity factors are too\nlow for economical operation. Adding energy storage to increase the\ncapacity factor of solar electricity triples the capital cost of the\nprocess. By updating research priorities based on fundamental electrolyzer\nbehavior, we hope this work accelerates the practical application\nof CO<sub>2</sub> reduction.