Raquel Aymerich Armengol1,Miquel Vega Paredes1,Andrea Mingers1,Rajib Sahu1,Christina Scheu1,Siyuan Zhang1,Joohyun Lim2
Max-Planck-Institut für Eisenforschung1,Kangwon National University2
Raquel Aymerich Armengol1,Miquel Vega Paredes1,Andrea Mingers1,Rajib Sahu1,Christina Scheu1,Siyuan Zhang1,Joohyun Lim2
Max-Planck-Institut für Eisenforschung1,Kangwon National University2
2D molybdenum disulfide (MoS<sub>2</sub>) is regarded as an excellent Pt-alternative electrocatalyst for hydrogen evolution (HER). Several approaches have been reported to enhance the activity of MoS<sub>2 </sub>catalysts, e.g. 1T phase selection, dopant introduction and substrate engineering. Nevertheless, the electrochemical stability of such MoS<sub>2</sub>-based materials remains controversial. Herein, we present new development on methods to assess the HER stability of 2D MoS<sub>2</sub>-based catalysts. Beyond thorough characterization by high-resolution (scanning) transmission electron microscopy ((S)TEM) and associated characterization techniques, the corrosion of 2D MoS<sub>2</sub> electrodes on different conducting substrates is studied in operando by scanning flow cell coupled to an inductively coupled plasma mass spectrometer (SFC-ICPMS). This method allows us to compare the effect of different conducting substrates and dopants on the stability as a function of HER current and overpotential. To gain further insights on the corrosion mechanisms and the evolution of the phases and morphology of the 2D MoS<sub>2</sub> catalysts, this data is complemented by performing electrochemical measurements in identical location (S)TEM conditions (IL-STEM). Based on the methodology, we provide new perspectives on the stability of 2D MoS<sub>2</sub> catalysts and shed light on their HER degradation mechanisms.