skip to main content

DOE PAGESDOE PAGES

Title: Importance of Low Dimensional CeO x Nanostructures in Pt/CeO x –TiO 2 Catalysts for the Water–Gas Shift Reaction

CO 2 and H 2 production from the water–gas shift (WGS) reaction was studied over Pt/CeO x–TiO 2 catalysts with incremental loadings of CeO x, which adopts variations in the local morphology. The lowest loading of CeO x (1 wt % to 0.5 at. %) that is configured in its smallest dimensions exhibited the best WGS activity over larger dimensional structures. We attribute this to several factors including the ultrafine dispersed one-dimensional nanocluster geometry, a large concentration of Ce 3+ and enhanced reducibility of the low loadings. We utilized several in situ experiments to monitor the active state of the catalyst during the WGS reaction. X-ray diffraction (XRD) results showed lattice expansion that indicated reduced ceria was prevalent during the WGS reaction. On the surface, Ce 3+ related hydroxyl groups were identified by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The enhanced reducibility of the catalyst with the introduction of ceria was further revealed by H 2-temperature programed reduction (H 2-TPR) and good thermal stability was confirmed by in situ environmental transmission electron microscopy (ETEM). Finally, we also investigated the formation of the low dimensional structures during catalyst preparation, through a two-stage crystal growth of ceria crystallite on TiO 2more » nanoparticle: fine crystallites ~1D formed at ~250 °C, followed by crystal growth into 2D chain and 3D particle from 250–400 °C.« less
Authors:
; ; ; ORCiD logo ; ; ; ; ; ORCiD logo
Publication Date:
Report Number(s):
BNL-113651-2017-JA
Journal ID: ISSN 1932-7447; R&D Project: CO009; KC0302010
Grant/Contract Number:
SC00112704
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 121; Journal Issue: 12; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1347370