Quantifying the density and utilization of active sites in non-precious metal oxygen electroreduction catalysts

• DOI: 10.1038/ncomms9618
• Publication Date: 2015-10-21T12:20:57Z
• Authors: Nastaran Ranjbar ...; Ulrike I. Kramm; Julian Steinberg; Yuanjian Zhang; Arne Thomas; Tobias Reier; Jens-Peter Parakn...; Peter Strasser
• Keywords: Bimetallic strip; Chemisorption; Precious metal

Abstract Carbon materials doped with transition metal and nitrogen are highly active, non-precious catalysts for the electrochemical conversion of molecular oxygen in fuel cells, air batteries, electrolytic processes. However, accurate measurement their intrinsic turn-over frequency active-site density based on centres bulk surface has remained difficult to date, which hampered a more rational catalyst design. Here we report successful quantification surface-based associated values mono- bimetallic Fe/N-doped carbons using combination chemisorption, desorption 57 Fe Mössbauer spectroscopy techniques. Our general approach yields an experimental descriptor activity utilization, aiding development process enabling previously unachieved level understanding reactivity trends owing deconvolution site activity.