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Title: Multiple redox mechanisms for water-gas shift reaction on Fe3O4 (1 1 1) surface: A density functional theory and mean-field microkinetic modeling study

Journal Article · · Applied Surface Science
ORCiD logo [1]; ORCiD logo [2]
  1. Purdue Univ., West Lafayette, IN (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
  2. Purdue Univ., West Lafayette, IN (United States)

In this work, we investigated redox mechanisms for the high temperature (HT) water–gas shift reaction (WGSR) on the Fe3O4 (1 1 1) surface using density functional theory (DFT) calculations and mean-field microkinetic modeling (MKM). The redox pathways branched into three Langmuir-Hinshelwood processes (LH1, LH2 and LH3) and one Mars-van-Krevelen (MVK) process (in the presence of oxygen vacancy) from multidentate binding of CO and CO2 over four available reactive sites (Feoct2, Fetet1, Fe bridge, and O1). We found that the LH1 and LH2 processes have CO adsorption at a single iron site (Feoct2 or Fetet1), while the LH3 and MVK processes have stronger chemisorption of CO or CO2 by both the Feoct2 site and the O1 site. From the mechanistic study of these reaction path, we recognized that availability of O1 sites was key to proceed to either CO oxidation by the single site (LH1, LH2) or by the dual site (LH3, MVK). We observed that the reaction energetics were significantly different in the CO oxidation steps, where the single or dual site results in markedly different apparent activation energy (73–281 kJ/mol) and reaction rates (10-3–10-10 mol∙m-2∙s-1) among the four reaction mechanisms. The utilization of mean field MKM with DFT reaction energetics helps explain the experimental debates for the catalytic reaction details as well as providing a possible direction to engineer the catalyst with higher activity.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1975342
Journal Information:
Applied Surface Science, Vol. 630, Issue 1; ISSN 0169-4332
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (70)

Generalized Gradient Approximation Made Simple journal October 1996
Magnetite Fe 3 O 4 (111) Surfaces: Impact of Defects on Structure, Stability, and Electronic Properties journal August 2015
Water adsorption on the Fe 3 O 4 (111) surface: dissociation and network formation journal January 2018
Vibrational properties of CO2 adsorbed on the Fe3O4 (111) surface: Insights gained from DFT journal March 2020
Projector augmented-wave method journal December 1994
DFT+U Study of Molecular and Dissociative Water Adsorptions on the Fe 3 O 4 (110) Surface journal April 2013
Modeling the Water-Gas Shift Reaction journal October 1974
Defects and inhomogeneities in Fe 3 O 4 (111) thin film growth on Pt(111) journal October 2012
Surface chemistry and catalysis on well-defined epitaxial iron-oxide layers journal March 2002
A grid-based Bader analysis algorithm without lattice bias journal January 2009
The multiple roles for catalysis in the production of H2 journal January 1999
High coverage hydrogen adsorption on the Fe3O4(110) surface journal October 2015
Electron-energy-loss spectra and the structural stability of nickel oxide: An LSDA+U study journal January 1998
Thermodynamic stability and atomic and electronic structure of reduced Fe 3 O 4 (111) single-crystal surfaces journal August 2007
Structures of Fe 3 O 4 (111) surfaces observed by scanning tunneling microscopy journal April 1996
Theoretical study of the termination of the Fe3O4 (111) surface journal December 1999
Surface properties of the clean and Au/Pd covered Fe3O4(111): DFT andDFT+Ustudy journal March 2012
Water Interaction with Iron Oxides journal November 2015
Fischer-Tropsch Synthesis: Impact of Pretreatment of Ultrafine iron Oxide upon Catalyst Structure and Selectivity journal January 1993
Kinetics of high-temperature water-gas shift reaction over two iron-based commercial catalysts using simulated coal-derived syngases journal January 2009
Gasreaktionen in der chemischen Kinetik. II journal May 1899
Resolving the Reaction Mechanism for H 2 Formation from High-Temperature Water–Gas Shift by Chromium–Iron Oxide Catalysts journal March 2016
In situ/operando studies for the production of hydrogen through the water-gas shift on metal oxide catalysts journal January 2013
Termination and Verwey transition of the (111) surface of magnetite studied by scanning tunneling microscopy and first-principles calculations journal June 2010
M�ssbauer spectroscopy study of iron-based catalysts used in Fischer-Tropsch synthesis journal March 1995
Promotion Mechanisms of Iron Oxide-Based High Temperature Water–Gas Shift Catalysts by Chromium and Copper journal June 2016
A climbing image nudged elastic band method for finding saddle points and minimum energy paths journal December 2000
In situ gravimetric studies of the regenerative mechanism for water-gas shift over magnetite: Equilibrium and kinetic measurements in CO2/CO and H2O/H2 gas mixtures journal September 1982
Surface Termination of Fe 3 O 4 (111) Films Studied by CO Adsorption Revisited journal June 2017
A perspective on chromium-Free iron oxide-based catalysts for high temperature water-gas shift reaction journal August 2018
Investigation of the rate-controlling step of the water gas shift reaction with use of various isotopic tracers journal January 1988
Water Gas Shift Catalysis journal September 2009
Surface structure and water adsorption on Fe 3 O 4 ( 111 ) : Spin-density functional theory and on-site Coulomb interactions journal February 2008
Defect structures on epitaxial Fe 3 O 4 ( 111 ) films journal October 1999
Water adsorption and growth of ice on epitaxial Fe3O4(111), FeO(111) and Fe2O3(biphase) journal April 2003
Relationship between temperature-programmed reduction profile and activity of modified ferrite-based catalysts for WGS reaction journal February 2008
Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set journal July 1996
Dynamic operation of water gas shift reaction over Fe2O3/Cr2O3/CuO catalyst in Pd/Al2O3 membrane reactor journal January 2018
Fe3O4 surface electronic structures and stability from GGA+U journal May 2012
Influence of the exchange screening parameter on the performance of screened hybrid functionals journal December 2006
Density functional theory study on the interaction of CO2 with Fe3O4(111) surface journal August 2016
CO 2 Adsorption on Magnetite Fe 3 O 4 (111) journal November 2018
Water on FeO(111) and Fe 3 O 4 (111):  Adsorption Behavior on Different Surface Terminations † journal April 2000
Stationary and transient kinetics of the high temperature water-gas shift reaction journal April 1996
Dynamics of CrO 3 –Fe 2 O 3 Catalysts during the High-Temperature Water-Gas Shift Reaction: Molecular Structures and Reactivity journal June 2016
Elucidation of the Reaction Mechanism for High-Temperature Water Gas Shift over an Industrial-Type Copper–Chromium–Iron Oxide Catalyst journal April 2019
Determining Number of Active Sites and TOF for the High-Temperature Water Gas Shift Reaction by Iron Oxide-Based Catalysts journal February 2016
Density Function Theory Study of CO Adsorption on Fe3O4(111) Surface journal June 2006
Ab initio molecular-dynamics simulation of the liquid-metal–amorphous-semiconductor transition in germanium journal May 1994
Structures and energetics of CO2 adsorption on the Fe3O4 (111) surface journal September 2018
Mechanistic Study on Water Gas Shift Reaction on the Fe 3 O 4 (111) Reconstructed Surface journal December 2015
CO adsorption on Fe3O4(1 1 1) with regular and biphase terminations journal March 2020
CO adsorption, oxidation and carbonate formation mechanisms on Fe3O4 surfaces journal January 2017
Adsorption or deoxidation of H2 interacted with Fe3O4 surface under different H coverage: A DFT study journal February 2020
Hydrogen production by methane decomposition: A review journal February 2010
DFT models for active sites on high temperature water-gas shift catalysts journal September 2008
Mechanism and microkinetics of the Fischer–Tropsch reaction journal January 2013
Semiempirical GGA-type density functional constructed with a long-range dispersion correction journal January 2006
Activation and deactivation of the commercial‐type CuO–Cr 2 O 3 –Fe 2 O 3 high temperature shift catalyst journal November 2019
Ab initio DFT + U predictions of tensile properties of iron oxides journal January 2010
The Optimally Performing Fischer-Tropsch Catalyst journal August 2014
A dynamic study of the water-gas shift reaction over an industrial ferrochrome catalyst journal August 1988
Water-gas shift reaction over chromia-promoted magnetite. Use of temperature-programmed desorption and chemical trapping in the study of the reaction mechanism journal July 1990
The surface structure of Fe3O4(111) films as studied by CO adsorption journal November 2004
Electrical and magnetic transport properties of Fe3O4thin films on a GaAs(100) substrate journal November 2007
Performance of water gas shift reaction catalysts: A review journal October 2018
Density Functional Theory Study of Water Dissociative Chemisorption on the Fe 3 O 4 (111) Surface journal November 2010
Structural Evolution of α-Fe2O3(0001) Surfaces Under Reduction Conditions Monitored by Infrared Spectroscopy journal June 2019
Methane-Steam Reforming journal January 1980
Bulk and surface phases of iron oxides in an oxygen and water atmosphere at low pressure journal January 2001