Please use this identifier to cite or link to this item: http://hdl.handle.net/10995/102724
Title: Tuning the activity/stability balance of anion doped CoSxSe2−x dichalcogenides
Authors: Li, Y.
Polakovic, T.
Curtis, J.
Shumlas, S. L.
Chatterjee, S.
Intikhab, S.
Chareev, D. A.
Volkova, O. S.
Vasiliev, A. N.
Karapetrov, G.
Snyder, J.
Issue Date: 2018
Publisher: Academic Press Inc.
Citation: Tuning the activity/stability balance of anion doped CoSxSe2−x dichalcogenides / Y. Li, T. Polakovic, J. Curtis, et al. — DOI 10.1016/j.jcat.2018.07.030 // Journal of Catalysis. — 2018. — Vol. 366. — P. 50-60.
Abstract: We present a thorough assessment of the compositional dependent hydrogen evolution reaction (HER) activity and stability for Co-based mixed chalcogen, CoSxSe2−x, transition metal dichalcogenides (TMDs). In direct contrast to other reports on mixed chalcogen TMDs that have been limited to Mo and W, we observe a decrease in HER activity for any departure from the pure, single chalcogen composition, CoS2 and CoSe2. The single chalcogen TMDs are found to have nearly identical HER activity. Bulk resistivity of the pure and mixed chalcogen TMDs as well as the charge transfer resistance for the HER are found to be most optimal for CoSe2. However, CoSe2 is predicted to have an endothermic hydrogen adsorption free energy in contrast to the slightly exothermic hydrogen adsorption free energy for CoS2. This highlights the convolution of hydrogen adsorption free energy and material conductivity in determining the HER activity for even metallic conducting TMDs. Sulfur-rich Co-based TMDs with a pyrite-type crystal structure are found to quickly deactivate through loss of Co and formation of passivating reduced sulfur species at the surface while Se-rich compositions are observed to be more stable. Therefore, with an HER activity matching that of CoS2, but with a dramatic improvement in stability, CoSe2 breaks away from the traditional inverse activity – stability relationship and represents a promising non-PGM HER electrocatalyst for acidic PEM electrolyzers. © 2018 Elsevier Inc.
Keywords: ANION DOPING
ELECTROCATALYSIS
HYDROGEN EVOLUTION REACTION
TRANSITION METAL DICHALCOGENIDES
CHARGE TRANSFER
CRYSTAL STRUCTURE
ELECTROCATALYSIS
ELECTROCATALYSTS
FREE ENERGY
GAS ADSORPTION
PYRITES
SULFUR
TRANSITION METALS
ANION DOPING
CHARGE TRANSFER RESISTANCE
HYDROGEN ADSORPTION
HYDROGEN EVOLUTION REACTIONS
MATERIAL CONDUCTIVITIES
PEM ELECTROLYZERS
REDUCED SULFUR SPECIES
TRANSITION METAL DICHALCOGENIDES
SELENIUM COMPOUNDS
URI: http://hdl.handle.net/10995/102724
Access: info:eu-repo/semantics/openAccess
SCOPUS ID: 85051392868
PURE ID: 7780111
b9fb4e9c-6625-4fd8-8823-651fb15bc685
ISSN: 219517
DOI: 10.1016/j.jcat.2018.07.030
Appears in Collections:Научные публикации, проиндексированные в SCOPUS и WoS CC

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