Nanocrystalline Fe60Co20Si10B10 as a cathode catalyst for alkaline water electrolysis: Impact of surface activation

Nanocrystalline Fe60Co20Si10B10, prepared by ball milling atomised powder, was studied as a hydrogen evolution reaction catalyst for alkaline water electrolysis. Two application-oriented aspects of this material were studied: (i) Surface activation of the catalyst (cyclic voltammetry and leaching in 1 mol dm(-3) potassium hydroxide) and (ii) the composition of a catalyst layer (ratio of the amount of catalyst to the polymer binder). Polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene with DABCO functional groups (PSEBS-CM-DABCO) was used as an anion-selective binder. The catalytic activity of the material was evaluated by means of Tafel analysis and by recording load curves under alkaline water electrolysis conditions. The results revealed that both activation procedures increase the activity of the Fe60Co20Si10B10 catalyst by almost 50% compared to as-received material. The most suitable ratio of catalyst to binder was determined as 70: 30. The catalyst remained stable and active in the stability test performed. (c) 2019 Elsevier Ltd. All rights reserved.