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Title: A Rh xS y/C Catalyst for the Hydrogen Oxidation and Hydrogen Evolution Reactions in HBr

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. The 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 0more » V and 0.65 V vs. RHE. Scans with upper voltage limit beyond 0.65 V led to decreased and unreproducible ECSA measurements.« less
 [1] ;  [1] ;  [2] ;  [2] ;  [3] ;  [3] ;  [4] ;  [4]
  1. Univ. of Kansas, Lawrence, KS (United States)
  2. Univ. of California, Santa Barbara, CA (United States)
  3. Kansas State Univ., Manhattan, KS (United States)
  4. National Taiwan University of Science & Technology, Tapei (Taiwan)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of the Electrochemical Society
Additional Journal Information:
Journal Volume: 162; Journal Issue: 4; Journal ID: ISSN 0013-4651
The Electrochemical Society
Research Org:
TVN Systems, Inc., Lawrence, KS (United States)
Sponsoring Org:
USDOE Advanced Research Projects Agency - Energy (ARPA-E)
Country of Publication:
United States
OSTI Identifier: