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Title: A RhxSy/C Catalyst for the Hydrogen Oxidation and Hydrogen Evolution Reactions in HBr

Abstract

Rhodium sulfide (Rh2S3) on carbon support was synthesized by refluxing rhodium chloride with ammonium thiosulfate. Thermal treatment of Rh2S3 at high temperatures (600 degrees C to 850 degrees C) in presence of argon resulted in the transformation of Rh2S3 into Rh3S4, Rh17S15 and Rh which were characterized by TGA/DTA, XRD, EDX, and deconvolved XPS analyses. The catalyst particle size distribution ranged from 3 to 12 nm. Cyclic voltammetry and rotating disk electrode measurements were used to evaluate the catalytic activity for hydrogen oxidation and evolution reactions in H2SO4 and HBr solutions. The thermally treated catalysts show high activity for the hydrogen reactions. The exchange current densities (i(o)) of the synthesized RhxSy catalysts in H-2-saturated 1M H2SO4 and 1M HBr for HER and HOR were 0.9 mA/cm(2) to 1.0 mA/cm(2) and 0.8 to 0.9 mA/cm(2), respectively. The lower i(o) values obtained in 1M HBr solution compared to in H2SO4 might be due to the adsorption of Br- on the active surface. Stable electrochemical active surface area (ECSA) of RhxSy catalyst was obtained for CV scan limits between 0 V and 0.65 V vs. RHE. Scans with upper voltage limit beyond 0.65 V led to decreased and unreproducible ECSA measurements. (C) Themore » Author(s) 2015. Published by ECS. All rights reserved.« less

Authors:
; ; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE Advanced Research Projects Agency - Energy (ARPA-E)
OSTI Identifier:
1211500
DOE Contract Number:
DE-AR0000262
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of the Electrochemical Society; Journal Volume: 162; Journal Issue: 4
Country of Publication:
United States
Language:
English

Citation Formats

Masud, J, Nguyen, TV, Singh, N, McFarland, E, Ikenberry, M, Hohn, K, Pan, CJ, and Hwang, BJ. A RhxSy/C Catalyst for the Hydrogen Oxidation and Hydrogen Evolution Reactions in HBr. United States: N. p., 2015. Web. doi:10.1149/2.0901504jes.
Masud, J, Nguyen, TV, Singh, N, McFarland, E, Ikenberry, M, Hohn, K, Pan, CJ, & Hwang, BJ. A RhxSy/C Catalyst for the Hydrogen Oxidation and Hydrogen Evolution Reactions in HBr. United States. doi:10.1149/2.0901504jes.
Masud, J, Nguyen, TV, Singh, N, McFarland, E, Ikenberry, M, Hohn, K, Pan, CJ, and Hwang, BJ. 2015. "A RhxSy/C Catalyst for the Hydrogen Oxidation and Hydrogen Evolution Reactions in HBr". United States. doi:10.1149/2.0901504jes.
@article{osti_1211500,
title = {A RhxSy/C Catalyst for the Hydrogen Oxidation and Hydrogen Evolution Reactions in HBr},
author = {Masud, J and Nguyen, TV and Singh, N and McFarland, E and Ikenberry, M and Hohn, K and Pan, CJ and Hwang, BJ},
abstractNote = {Rhodium sulfide (Rh2S3) on carbon support was synthesized by refluxing rhodium chloride with ammonium thiosulfate. Thermal treatment of Rh2S3 at high temperatures (600 degrees C to 850 degrees C) in presence of argon resulted in the transformation of Rh2S3 into Rh3S4, Rh17S15 and Rh which were characterized by TGA/DTA, XRD, EDX, and deconvolved XPS analyses. The catalyst particle size distribution ranged from 3 to 12 nm. Cyclic voltammetry and rotating disk electrode measurements were used to evaluate the catalytic activity for hydrogen oxidation and evolution reactions in H2SO4 and HBr solutions. The thermally treated catalysts show high activity for the hydrogen reactions. The exchange current densities (i(o)) of the synthesized RhxSy catalysts in H-2-saturated 1M H2SO4 and 1M HBr for HER and HOR were 0.9 mA/cm(2) to 1.0 mA/cm(2) and 0.8 to 0.9 mA/cm(2), respectively. The lower i(o) values obtained in 1M HBr solution compared to in H2SO4 might be due to the adsorption of Br- on the active surface. Stable electrochemical active surface area (ECSA) of RhxSy catalyst was obtained for CV scan limits between 0 V and 0.65 V vs. RHE. Scans with upper voltage limit beyond 0.65 V led to decreased and unreproducible ECSA measurements. (C) The Author(s) 2015. Published by ECS. All rights reserved.},
doi = {10.1149/2.0901504jes},
journal = {Journal of the Electrochemical Society},
number = 4,
volume = 162,
place = {United States},
year = 2015,
month = 1
}
  • Rhodium sulfide (Rh 2S 3) on carbon support was synthesized by refluxing rhodium chloride with ammonium thiosulfate. Thermal treatment of Rh 2S 3 at high temperatures (600°C to 850°C) in presence of argon resulted in the transformation of Rh 2S 3 into Rh 3S 4, Rh 17S 15 and Rh which were characterized by TGA/DTA, XRD, EDX, and deconvolved XPS analyses. The catalyst particle size distribution ranged from 3 to 12 nm. Cyclic voltammetry and rotating disk electrode measurements were used to evaluate the catalytic activity for hydrogen oxidation and evolution reactions in H 2SO 4 and HBr solutions. Themore » thermally treated catalysts show high activity for the hydrogen reactions. The exchange current densities (i o) of the synthesized Rh xS y catalysts in H 2-saturated 1M H 2SO 4 and 1M HBr for HER and HOR were 0.9 mA/cm 2 to 1.0 mA/cm 2 and 0.8 to 0.9 mA/cm 2, respectively. The lower i o values obtained in 1M HBr solution compared to in H 2SO 4 might be due to the adsorption of Br - on the active surface. Stable electrochemical active surface area (ECSA) of Rh xS y catalyst was obtained for CV scan limits between 0 V and 0.65 V vs. RHE. Scans with upper voltage limit beyond 0.65 V led to decreased and unreproducible ECSA measurements.« less
  • Deactivation of 2.0 to 15 nm Pt crystallites supported on alumina and Pt black was studied in a fixed-bed differential reactor during NH/sub 3/ oxidation by molecular oxygen between 368 and 473/sup 0/K. Marked deactivation caused by surface oxidation took place during the first 12 hr on stream. Deactivation occurred only in the presence of both reactants, and was more severe with smaller crystallites and at lower temperatures. The rate decay was best described by a second-order deactivation process. At 433/sup 0/K oxygen present in the deactivated 2.7 nm crystallites was about 5 atoms per surface Pt atom, giving anmore » estimated bulk composition of PtO/sub 1/./sub 7/. For the 15.5 nm crystallites the oxygen present in the deactivated crystallites was about 7 atoms per surface Pt atom but the resultant bulk composition was PtO/sub 0/./sub 5/. Deactivation was reversible and activity could be restored by raising the temperature above 473/sup 0/K or by reacting with H/sub 2/ or NH/sub 3/. Deactivated catalyst slowly released oxygen in reaction with NH/sub 3/ chemisorbed on the support after the feed O/sub 2/ and NH/sub 3/ were turned off. This is a form of reverse spillover. Platinum black studies confirmed the results with the supported catalysts.« less
  • A variety of supported catalysts were prepared by the chemical deposition of Pt and Pt-Ru particles on chemically prepared poly(3,4-ethylenedioxythiophene)/poly(styrene-4-sulfonate) (PEDOT/PSS) and PEDOT/polyvinylsulfate (PVS) composites. The polymer particles were designed to provide a porous, proton-conducting and electron-conducting catalyst support for use in fuel cells. These polymer-supported catalysts were characterized by electron microscopy, impedance spectroscopy, cyclic voltammetry, and conductivity measurements. Their catalytic activities toward hydrogen and methanol oxidation and oxygen reduction were evaluated in proton exchange membrane fuel-cell-type gas diffusion electrodes. Activities for oxygen reduction comparable to that obtained with a commercial carbon-supported catalyst were observed, whereas those for hydrogen andmore » methanol oxidation were significantly inferior, although still high for prototype catalysts.« less