Highly selective and productive reduction of carbon dioxide to multicarbon products via in situ CO management using segmented tandem electrodes

Electrochemical CO2 reduction provides a promising route to the sustainable generation of valuable chemicals and fuels. Tandem catalysts enable sequential CO2-to-CO CO-to-multicarbon (C2+) product conversions on complementary active sites, produce high C2+ Faradaic efficiency (FE). Unfortunately, previous tandem exhibit poor management CO intermediates, which diminishes FE. Here, we design segmented gas-diffusion electrodes (s-GDEs) in CO-selective catalyst layer (CL) segment at inlet prolongs residence time subsequent C2+-selective segment, enhancing conversion. This phenomenon enables increases both utilization current density for Cu/Ag s-GDE compared pure Cu, by increasing *CO coverage within Cu CL. Lastly, develop Cu/Fe-N-C with 90% FE partial (jC2+) exceeding 1 A cm−2. These results prove importance transport establish principles improve jC2+ reduction. Poor gas flow limits (two-catalyst) electrocatalytic authors electrode architecture that (produced first catalyst) second catalyst, resulting production further reduced yields.