The high-energy-density C3 fuel n-propanol is desired from CO2/CO electroreduction, as evidenced by propanol’s high market price per tonne (approximately US$ 1,400–1,600). However, CO electroreduction to n-propanol has shown low selectivity, limited production rates and poor stability. Here we report catalysts, identified using computational screening, that simultaneously facilitate multiple carbon–carbon coupling, stabilize C2 intermediates and promote CO adsorption, all leading to improved n-propanol electrosynthesis. Experimentally we construct the predicted optimal electrocatalyst based on silver–ruthenium co-doped copper. We achieve, at 300 mA cm−2, a high n-propanol Faradaic efficiency of 36% ± 3%, a C2+ Faradaic efficiency of 93% and single-pass CO conversion of 85%. The system exhibits 100 h stable n-propanol electrosynthesis. Technoeconomic analysis based on the performance of the pilot system projects profitability.