Pulsed Electrolysis Promotes Catalyst Activity in Dilute CO2 Streams

Abstract Industrial CO2 streams vary widely in composition, from pure to as low as 3%, posing challenges for purification or direct conversion. Electrochemical reduction offers a route for converting dilute CO2 streams but faces severe mass transport limitations. This study demonstrates that pulsed electrolysis effectively overcomes these limitations, enhancing CO2 electroreduction across variable feed compositions and current densities, particularly at low CO2 concentrations and high current densities. At 25% CO2 and 400 mA cm−2, pulsing improved selectivity from 25.6 to 78.6%, production rate from 13.7 to 21.0 mol m−2 h−1, and energy productivity from 0.77 to 2.59 mol kWh−1. A dynamic, multiphysics continuum model confirms a 64% increase in CO2 concentration within the catalyst layer during pulsing, resolving the transient chemical microenvironment. These findings establish pulsed electrolysis as a viable strategy for converting dilute industrial CO2 streams into valuable feedstocks, bypassing costly pre-separation.