eprintid: 1492818
rev_number: 45
eprint_status: archive
userid: 608
dir: disk0/01/49/28/18
datestamp: 2016-06-10 14:44:36
lastmod: 2021-09-27 22:39:38
status_changed: 2016-06-10 14:44:36
type: article
metadata_visibility: show
creators_name: Wang, F
creators_name: Büchel, R
creators_name: Savitsky, A
creators_name: Zalibera, M
creators_name: Widmann, D
creators_name: Pratsinis, SE
creators_name: Lubitz, W
creators_name: Schüth, F
title: In Situ EPR Study of the Redox Properties of CuO–CeO 2 Catalysts for Preferential CO Oxidation (PROX)
ispublished: pub
divisions: UCL
divisions: B04
divisions: C05
divisions: F43
keywords: CuO−CeO2 catalyst; in situ spectroscopy; EPR; redox mechanism; preferential CO oxidation
note: Copyright © 2016 American Chemical Society. This is the author accepted manuscript version of the article published by the American Chemical Society in ACS Catalysis and available at http://dx.doi.org/10.1021/acscatal.6b00589
abstract: Understanding the redox properties of metal oxide based catalysts is a major task in catalysis research. In situ electron paramagnetic resonance (EPR) spectroscopy is capable of monitoring the change of metal ion valences and formation of active sites during redox reactions, allowing for the identification of ongoing redox pathways. Here in situ EPR spectroscopy combined with online gas analysis, supported by ex situ X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), X-ray absorption near edge structure (XANES), temporal analysis of product (TAP), and mass spectrometry (MS) studies, was utilized to study the redox behavior of CuO–CeO2 catalysts under PROX conditions (preferential oxidation of carbon monoxide in hydrogen). Two redox mechanisms are revealed: (i) a synergetic mechanism that involves the redox pair Ce4+/Ce3+ during oxidation of Cu0/Cu+ species to Cu2+ and (ii) a direct mechanism that bypasses the redox pair Ce4+/Ce3+. In addition, EPR experiments with isotopically enriched 17O2 established the synergetic mechanism as the major redox reaction pathway. The results emphasize the importance of the interactions between Cu and Ce atoms for catalyst performance. With the guidance of these results, an optimized CuO–CeO2 catalyst could be designed. A rather wide temperature operation window of 11 K (from 377 to 388 K), with 99% conversion efficiency and 99% selectivity, was achieved for the preferential oxidation of CO in a H2 feed.
date: 2016-06-03
date_type: published
official_url: http://dx.doi.org/10.1021/acscatal.6b00589
oa_status: green
full_text_type: other
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 1129435
doi: 10.1021/acscatal.6b00589
lyricists_name: Wang, Feng
lyricists_id: FWANG76
actors_name: Wang, Feng
actors_id: FWANG76
actors_role: owner
full_text_status: public
publication: ACS Catalysis
volume: 6
number: 6
pagerange: 3520-3530
issn: 2155-5435
citation:        Wang, F;    Büchel, R;    Savitsky, A;    Zalibera, M;    Widmann, D;    Pratsinis, SE;    Lubitz, W;           Wang, F;  Büchel, R;  Savitsky, A;  Zalibera, M;  Widmann, D;  Pratsinis, SE;  Lubitz, W;  Schüth, F;   - view fewer <#>    (2016)    In Situ EPR Study of the Redox Properties of CuO–CeO 2 Catalysts for Preferential CO Oxidation (PROX).                   ACS Catalysis , 6  (6)   pp. 3520-3530.    10.1021/acscatal.6b00589 <https://doi.org/10.1021/acscatal.6b00589>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/1492818/3/Wang%202016%20%20In%20Situ%20EPR%20Study.pdf