PMID- 20442915
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20100818
LR  - 20100520
IS  - 1463-9084 (Electronic)
IS  - 1463-9076 (Linking)
VI  - 12
IP  - 21
DP  - 2010 Jun 7
TI  - Determination of CO, H2O and H2 coverage by XANES and EXAFS on Pt and Au during 
      water gas shift reaction.
PG  - 5678-93
LID - 10.1039/c000240m [doi]
AB  - The turn-over-rate (TOR) for the water gas shift (WGS) reaction at 200 degrees C, 
      7% CO, 9% CO(2), 22% H(2)O, 37% H(2) and balance Ar, of 1.4 nm Au/Al(2)O(3) is 
      approximately 20 times higher than that of 1.6 nm Pt/Al(2)O(3). Operando EXAFS 
      experiments at both the Au and Pt L(3) edges reveal that under reaction 
      conditions, the catalysts are fully metallic. In the absence of adsorbates, the 
      metal-metal bond distances of Pt and Au catalysts are 0.07 A and 0.13 A smaller 
      than those of bulk Pt and Au foils, respectively. Adsorption of H(2) or CO on the 
      Pt catalysts leads to significantly longer Pt-Pt bond distances; while there is 
      little change in Au-Au bond distance with adsorbates. Adsorption of CO, H(2) and 
      H(2)O leads to changes in the XANES spectra that can be used to determine the 
      surface coverage of each adsorbate under reaction conditions. During WGS, the 
      coverage of CO, H(2)O, and H(2) are obtained by the linear combination fitting of 
      the difference XANES, or DeltaXANES, spectra. Pt catalysts adsorb CO, H(2), and 
      H(2)O more strongly than the Au, in agreement with the lower CO reaction order 
      and higher reaction temperatures.
FAU - Guo, Neng
AU  - Guo N
AD  - Chemical Sciences and Engineering Division, Argonne National Lab, Argonne, IL 
      60439-4837, USA.
FAU - Fingland, Bradley R
AU  - Fingland BR
FAU - Williams, W Damion
AU  - Williams WD
FAU - Kispersky, Vincent F
AU  - Kispersky VF
FAU - Jelic, Jelena
AU  - Jelic J
FAU - Delgass, W Nicholas
AU  - Delgass WN
FAU - Ribeiro, Fabio H
AU  - Ribeiro FH
FAU - Meyer, Randall J
AU  - Meyer RJ
FAU - Miller, Jeffrey T
AU  - Miller JT
LA  - eng
PT  - Journal Article
DEP - 20100504
PL  - England
TA  - Phys Chem Chem Phys
JT  - Physical chemistry chemical physics : PCCP
JID - 100888160
EDAT- 2010/05/06 06:00
MHDA- 2010/05/06 06:01
CRDT- 2010/05/06 06:00
PHST- 2010/05/06 06:00 [entrez]
PHST- 2010/05/06 06:00 [pubmed]
PHST- 2010/05/06 06:01 [medline]
AID - 10.1039/c000240m [doi]
PST - ppublish
SO  - Phys Chem Chem Phys. 2010 Jun 7;12(21):5678-93. doi: 10.1039/c000240m. Epub 2010 
      May 4.