The research team consisting of Ádám Vass, Prof. Balázs Endrődi, Gergely Ferenc Samu, Ádám Balog, Attila Kormányos, Serhiy Cherevko, and Prof. Csaba Janáky published "Local Chemical Environment Governs Anode Processes in CO2 Electrolyzers' today, October 7th, 2021. The open-access paper can be read in ACS Energy Letters, ACS Energy Lett. 2021, 6, XXX, 3801–3808. DOI: https://doi.org/10.1021/acsenergylett.1c01937  Download the PDF here.

Congratulations to the whole team!

Abstract: A major goal within the CO2 electrolysis community is to replace the generally used Ir anode catalyst with a more abundant material, which is stable and active for water oxidation under process conditions. Ni is widely applied in alkaline water electrolysis, and it has been considered as a potential anode catalyst in CO2 electrolysis. Here we compare the operation of electrolyzer cells with Ir and Ni anodes and demonstrate that, while Ir is stable under process conditions, the degradation of Ni leads to a rapid cell failure. This is caused by two parallel mechanisms: (i) a pH decrease of the anolyte to a near neutral value and (ii) the local chemical environment developing at the anode (i.e., high carbonate concentration). The latter is detrimental for zero-gap electrolyzer cells only, but the first mechanism is universal, occurring in any kind of CO2 electrolyzer after prolonged operation with recirculated anolyte.