PMID- 31021093
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20191120
IS  - 1520-5126 (Electronic)
IS  - 0002-7863 (Linking)
VI  - 141
IP  - 19
DP  - 2019 May 15
TI  - Elucidation of the Reaction Mechanism for High-Temperature Water Gas Shift over 
      an Industrial-Type Copper-Chromium-Iron Oxide Catalyst.
PG  - 7990-7999
LID - 10.1021/jacs.9b03516 [doi]
AB  - The water gas shift (WGS) reaction is of paramount importance for the chemical 
      industry, as it constitutes, coupled with methane reforming, the main industrial 
      route to produce hydrogen. Copper-chromium-iron oxide-based catalysts have been 
      widely used for the high-temperature WGS reaction industrially. The WGS reaction 
      mechanism by the CuCrFeO (x) catalyst has been debated for years, mainly between 
      a "redox" mechanism involving the participation of atomic oxygen from the 
      catalyst and an "associative" mechanism proceeding via a surface formate-like 
      intermediate. In the present work, advanced in situ characterization techniques 
      (infrared spectroscopy, temperature-programmed surface reaction (TPSR), 
      near-ambient pressure XPS (NAP-XPS), and inelastic neutron scattering (INS)) were 
      applied to determine the nature of the catalyst surface and identify surface 
      intermediate species under WGS reaction conditions. The surface of the CuCrFeO 
      (x) catalyst is found to be dynamic and becomes partially reduced under WGS 
      reaction conditions, forming metallic Cu nanoparticles on Fe(3)O(4). Neither in 
      situ IR not INS spectroscopy detect the presence of surface formate species 
      during WGS. TPSR experiments demonstrate that the evolution of CO(2) and H(2) 
      from the CO/H(2)O reactants follows different kinetics than the evolution of 
      CO(2) and H(2) from HCOOH decomposition (molecule mimicking the associative 
      mechanism). Steady-state isotopic transient kinetic analysis (SSITKA) (CO + 
      H(2)(16)O --> CO + H(2)(18)O) exhibited significant (16)O/(18)O scrambling, 
      characteristic of a redox mechanism. Computed activation energies for elementary 
      steps for the redox and associative mechanism by density functional theory (DFT) 
      simulations indicate that the redox mechanism is favored over the associative 
      mechanism. The combined spectroscopic, computational, and kinetic evidence in the 
      present study finally resolves the WGS reaction mechanism on the industrial-type 
      high-temperature CuCrFeO (x) catalyst that is shown to proceed via the redox 
      mechanism.
FAU - Polo-Garzon, Felipe
AU  - Polo-Garzon F
AUID- ORCID: 0000-0002-6507-6183
AD  - Chemical Sciences Division and Center for Nanophase Materials Sciences , Oak 
      Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States.
FAU - Fung, Victor
AU  - Fung V
AUID- ORCID: 0000-0002-3347-6983
AD  - Chemical Sciences Division and Center for Nanophase Materials Sciences , Oak 
      Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States.
AD  - Department of Chemistry , University of California , Riverside , California 92521 
      , United States.
FAU - Nguyen, Luan
AU  - Nguyen L
AD  - Departments of Chemical Engineering and Chemistry , The University of Kansas , 
      Lawrence , Kansas 66047 , United States.
FAU - Tang, Yu
AU  - Tang Y
AUID- ORCID: 0000-0001-9435-9310
AD  - Departments of Chemical Engineering and Chemistry , The University of Kansas , 
      Lawrence , Kansas 66047 , United States.
FAU - Tao, Franklin
AU  - Tao F
AUID- ORCID: 0000-0002-4916-6509
AD  - Departments of Chemical Engineering and Chemistry , The University of Kansas , 
      Lawrence , Kansas 66047 , United States.
FAU - Cheng, Yongqiang
AU  - Cheng Y
AUID- ORCID: 0000-0002-3263-4812
AD  - Neutron Scattering Division , Oak Ridge National Laboratory , Oak Ridge , 
      Tennessee 37831 , United States.
FAU - Daemen, Luke L
AU  - Daemen LL
AD  - Neutron Scattering Division , Oak Ridge National Laboratory , Oak Ridge , 
      Tennessee 37831 , United States.
FAU - Ramirez-Cuesta, Anibal J
AU  - Ramirez-Cuesta AJ
AD  - Neutron Scattering Division , Oak Ridge National Laboratory , Oak Ridge , 
      Tennessee 37831 , United States.
FAU - Foo, Guo Shiou
AU  - Foo GS
AD  - Chemical Sciences Division and Center for Nanophase Materials Sciences , Oak 
      Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States.
FAU - Zhu, Minghui
AU  - Zhu M
AUID- ORCID: 0000-0003-1593-9320
AD  - Operando Molecular Spectroscopy & Catalysis Laboratory, Department of Chemical 
      and Biomolecular Engineering , Lehigh University , Bethlehem , Pennsylvania 18015 
      , United States.
FAU - Wachs, Israel E
AU  - Wachs IE
AUID- ORCID: 0000-0001-5282-128X
AD  - Operando Molecular Spectroscopy & Catalysis Laboratory, Department of Chemical 
      and Biomolecular Engineering , Lehigh University , Bethlehem , Pennsylvania 18015 
      , United States.
FAU - Jiang, De-En
AU  - Jiang DE
AUID- ORCID: 0000-0001-5167-0731
AD  - Department of Chemistry , University of California , Riverside , California 92521 
      , United States.
FAU - Wu, Zili
AU  - Wu Z
AUID- ORCID: 0000-0002-4468-3240
AD  - Chemical Sciences Division and Center for Nanophase Materials Sciences , Oak 
      Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States.
LA  - eng
PT  - Journal Article
DEP - 20190501
PL  - United States
TA  - J Am Chem Soc
JT  - Journal of the American Chemical Society
JID - 7503056
EDAT- 2019/04/26 06:00
MHDA- 2019/04/26 06:01
CRDT- 2019/04/26 06:00
PHST- 2019/04/26 06:00 [pubmed]
PHST- 2019/04/26 06:01 [medline]
PHST- 2019/04/26 06:00 [entrez]
AID - 10.1021/jacs.9b03516 [doi]
PST - ppublish
SO  - J Am Chem Soc. 2019 May 15;141(19):7990-7999. doi: 10.1021/jacs.9b03516. Epub 
      2019 May 1.