These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
submitted on 27.08.2020 and posted on 28.08.2020by youyi sun, Alexey Ganin
Metal alloys have become ubiquitous choice as catalysts for electrochemical hydrogen evolution in alkaline media. However, scarce and expensive Pt remains the key electrocatalyst in acidic electrolytes making the search for earth-abundant and cheaper alternatives appealing. Herein, we present a facile and efficient synthetic route towards polycrystalline Co3Mo and Co6Mo7 metal alloys that achieve competitively low overpotentials of 115 mV and 160 mV at 10 mA cm–2 in 0.5 M H2SO4. Both alloys outperform Co and Mo metals which showed significantly higher overpotentials and lower current densities when tested under identical conditions. However, the low overpotential in Co3Mo comes at the price of stability. It rapidly becomes inactive when tested under applied potential bias. On the other hand, Co7Mo6 retains the current density over time without the evidence of current decay. The findings demonstrate that even in free-standing form and without nanostructuring polycrystalline bimetallic electrocatalysts could challenge the dominance of Pt in the acidic media if the ways for improving their stability were found.