Assessment issues on electrochemical catalysis for water splitting

A number of catalysts have been developed for electrochemical water electrolysis in the last decades, however, the inadequate understanding and the non-standard measurements result in inaccurate activity evaluation. Especially at present, water electrolysis aims to deal with higher-current-density scenario, and the exaggeration for catalysts heavily mislead to unnecessary trial and error in the real application. The dynamic lineage sweep voltammetry, as a universal estimation method to evaluate the activity of material, is discussed, including the issues on electrochemical assessment and the possible factors to inaccuracy. Accordingly, we cast our own opinions and suggestions in practice, such as building the reasonable electrolytic cell system, including the electrode position, size, electrolyte, cell types, scan rate, stirring, selection of the counter and reference electrodes, etc. The IR compensation on resistance and conversion of specific activity are also mentioned. We suggest that the researchers should operate in a standardized manner and obtain the authentic data, without intentionally hiding the tricky experiment settings.