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This content will become publicly available on December 27, 2018

Title: Inhibitive effect of Pt on Pd-hydride formation of Pd@Pt core-shell electrocatalysts: An in situ EXAFS and XRD study

In situ EXAFS and XRD have been used to study the electrochemical formation of hydride phases, H abs, in 0.5 M H 2SO 4 for a Pd/C catalyst and a series of Pd@Pt core-shell catalysts with varying Pt shell thickness, from 0.5 to 4 monolayers. Based on the XRD data a 3% lattice expansion is observed for the Pd/C core catalyst upon hydride formation at 0.0 V. In contrast, the expansion was ≤0.6% for all of the core-shell catalysts. The limited extent of the lattice expansion observed suggests that hydride formation, which may occur during periodic active surface area measurements conducting during accelerated aging tests or driven by H 2 crossover in PEM fuel cells, is unlikely to contribute significantly to the degradation of Pd@Pt core-shell electrocatalysts in contrast to the effects of oxide formation.
Authors:
 [1] ;  [2] ;  [3] ;  [2] ;  [2] ;  [4] ;  [5] ;  [2]
  1. Univ. of Southampton (United Kingdom). Dept. of Chemistry; SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource (SSRL)
  2. Univ. of Southampton (United Kingdom). Dept. of Chemistry
  3. Univ. of Southampton (United Kingdom). Dept. of Chemistry; Science and Technology Facilities Council (STFC), Harwell Campus, Oxford (United Kingdom). Diamond Light Source, Ltd.
  4. Univ. of Southampton (United Kingdom). Dept. of Chemistry; Ventacon UK, Gable Cottage, Crawley, Hampshire (United Kingdom)
  5. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource (SSRL)
Publication Date:
Grant/Contract Number:
AC02-76SF00515; AC02-98CH10886
Type:
Accepted Manuscript
Journal Name:
Electrochimica Acta
Additional Journal Information:
Journal Volume: 262; Journal Issue: C; Journal ID: ISSN 0013-4686
Publisher:
Elsevier
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; 25 ENERGY STORAGE; Electrocatalyst; EXAFS; XRD; Core-shell
OSTI Identifier:
1425664