Abstract
The application of metal-organic frameworks (MOFs) as electrocatalysts for small molecule activation has been an emerging topic of research. Previous studies have suggested that two-dimensional (2D) dithiolene-based MOFs are among the most active for the hydrogen evolution reaction (HER). Here, a three-dimensional (3D) dithiolene-based MOF, Cu[Ni(2,3-pyrazinedithiolate)2] (1), is evaluated as an electrocatalyst for the HER. In pH 1.3 aqueous electrolyte solution, 1 exhibits a catalytic onset at -0.43 V vs the reversible hydrogen electrode (RHE), an overpotential (η10mA/cm2) of 0.53 V to reach a current density of 10 mA/cm2, and a Tafel slope of 69.0 mV/dec. Interestingly, under controlled potential electrolysis, 1 undergoes an activation process that results in a more active catalyst with a 200 mV reduction in the catalytic onset and η10mA/cm2. It is proposed that the activation process is a result of the cleavage of Cu-N bonds in the presence of protons and electrons. This hypothesis is supported by various experimental studies and density functional theory calculations.
| Original language | English |
|---|---|
| Pages (from-to) | 34419-34427 |
| Number of pages | 9 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 13 |
| Issue number | 29 |
| DOIs | |
| State | Published - Jul 28 2021 |
| Externally published | Yes |
Funding
The research was primarily supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Award DE-SC0019236 (experimental studies) and the Nanoporous Materials Genome Center funded by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Award DE-FG02-17ER16362 (theoretical studies). Additional support was provided by the University of Southern California (USC), the USC Women in Science and Engineering, and the University of Minnesota. K.C. gratefully acknowledges the USC Dana and David Dornsife College of Letters, Arts and Sciences for a research fellowship. The authors are grateful to Prof. Jeffrey R. Long for providing the Cu[Ni(pdt)] MOF utilized in these studies. D.R., C.A.G., and L.G. would like to acknowledge Minnesota Supercomputing Institute for generous computing resources. XPS, EDX, and SEM data were collected at the Core Center of Excellence in Nano Imaging, USC. 2 The research was primarily supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences Geosciences and Biosciences under Award DE-SC0019236 (experimental studies) and the Nanoporous Materials Genome Center funded by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Award DE-FG02-17ER16362 (theoretical studies). Additional support was provided by the University of Southern California (USC), the USC Women in Science and Engineering and the University of Minnesota. K.C. gratefully acknowledges the USC Dana and David Dornsife College of Letters, Arts and Sciences for a research fellowship. The authors are grateful to Prof. Jeffrey R. Long for providing the Cu[Ni(pdt)2] MOF utilized in these studies. D.R., C.A.G., and L.G. would like to acknowledge Minnesota Supercomputing Institute for generous computing resources. XPS, EDX and SEM data were collected at the Core Center of Excellence in Nano Imaging, USC.
Keywords
- density functional theory
- dithiolene
- electrocatalysis
- hydrogen evolution
- metal-organic framework
