Stability and activity of non-noble based catalysts toward the hydrogen evolution reaction -feasible electrocatalysts in acidic medium?

• Published in: Angewandte Chemie International Edition 2017-06
• Main Authors: Ledendecker, Marc, Mondschein, Jared, Kasian, Olga, Geiger, Simon, Göhl, Daniel, Schalenbach, Max, Zeradjanin, Aleksandar, Cherevko, Serhiy, Schaak, Raymond E, Mayrhofer, Karl
• Format: Article
• Language: English
• Subjects: Catalysis; Chemical Sciences
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201704021

Fundamental understanding of the behavior of non-noble based materials toward the hydrogen evolution reaction is crucial for the successful implementation into practical devices. Through the implementation of a highly sensitive on-line inductively coupled plasma mass spectrometer coupled to a scanning flow cell, an activity and stability protocol for non-noble electrocatalysts is presented. The studied catalysts comprise a range of compositions, including metal carbides (WC), sulfides (MoS2), phosphides (Ni5P4, Co2P), their base metals (W, Ni, Mo, Co) and their activity, stability and degradation behavior was elaborated and compared to platinum. It is shown that the non-noble materials are stable at HER potentials but dissolve substantially when no current is flowing. Through pre- and post-characterization of the catalysts, explanations of their stability (thermodynamics and kinetics) are discussed, challenges for the application in real devices are analyzed, and strategies for circumventing dissolution are suggested. The precise correlation of metal dissolution with applied potential/current density allows for narrowing down suitable material choices as replacement for precious group metals as e.g. platinum and opens up new ways in finding cost-efficient, active and stable new-generation electrocatalysts