Chinese Journal of Catalysis ›› 2021, Vol. 42 ›› Issue (8): 1360-1369.DOI: 10.1016/S1872-2067(20)63682-8

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Fe/Co and Ni/Co-pentlandite type electrocatalysts for the hydrogen evolution reaction

Mathias Smialkowskia, David Tetzlaffa,b, Lars Hensgenc, Daniel Siegmundb, Ulf-Peter Apfela,b,*()   

  1. aInorganic Chemistry I – Ruhr University Bochum, Universitätsstrasse 150, 44801 Bochum, Germany
    bFraunhofer UMSICHT, Osterfelder Strasse 3, 46047 Oberhausen, Germany
    cTribotecc GmbH, Fleischmarkt 3-5, 1010 Vienna, Austria
  • Received:2020-03-30 Accepted:2020-03-30 Online:2021-08-18 Published:2020-11-23
  • Contact: Ulf-Peter Apfel
  • About author:*. E-Mail: ulf.apfel@rub.de, ulf.apfel@umsicht.fraunhofer.de
    First author contact:

    Contributed equally to this work.

  • Supported by:
    This work was supported by the Deutsche Forschungsgemeinschaft(AP242/2-1);This work was supported by the Deutsche Forschungsgemeinschaft(AP242/6-1);the Doctoral School Closed Car-bon Cycle Economy(DS CCCE);the Fraunhofer Internal Programs(Attract 097-602175);the Fraun-hofer Cluster of Excellence CINES

Abstract:

Metal-rich transition metal sulfides recently gained increasing attention as electrocatalysts for the hydrogen evolution reaction (HER), as they are capable to overcome major challenges faced by sulfide-rich metal catalysts such as limited conductivity and the necessity of nanostructuring. Herein, we present the synthesis, characterization and electrocatalytic investigation of ternary metal-rich sulfide composites FexCo9‒xS8 as well as NiyCo9‒yS8 (x = y = 0-4.5), which possess pentlandite-type structures. In this study, we show a stepwise alteration of the binary cobalt pentlandite Co9S8 and report on the replacement of cobalt with up to 4.5 equivalents of either iron or nickel. These altered pentlandite composites facilitate the proton reduction in acidic media at different temperatures. We furthermore show that the stoichiometric variation has a decisive influence on the electrochemical activation/deactivation behavior of the catalysts under reductive electrocatalytic conditions. Here, Co-deficient composites display an improved HER performance in contrast to Co9S8. Notably, Ni/Co compounds generally tend to show higher catalytic activities towards HER than their respective Fe/Co compounds.

Key words: Hydrogen, Pentlandite, Metal sulfides, Transition metals, Electrocatalysis