Catalysis

The group takes part in finding eficient, cost-effective and environment-friendly catalysts to reduce the dependence of society to non-renewable energy resources, such as fossil fuels. We employ first-principles computational methods to assess the catalytic activity and efficiency of transition metals and their oxides towards activation of industrially important reactions such as CO combustion; NOx reduction; and H2 and O2 generation.
We are also interested in studying "self-regulated" polymerization reactions that would be highly valuable in paints and coating industry.

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Recent related works

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We are researching the Pd-doped BaCeO3 self-regenerative catalyst. This entails an investigation of the catalytic reaction mechanism using ab initio atomistic thermodynamics. Furthermore, we want to understand how oxygen diffusion in Pd-doped BaCeO3 supports CO oxidation. In doing this, we are conducting both thermodynamic and kinetic studies based on first-principles calculations and the NEB (nudged elastic band) method for optimizing diffusion saddle points.

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Our research presents a computational study of chain transfer (to monomer, polymer, and solvent) reactions in self-initiated high-temperature homo-polymerization of alkyl acrylates (methyl, ethyl, and n-butyl acrylates). Several mechanisms for each of these reactions are studied using different functionals. The effect of the length of live polymer chains and the type of mono-radical that initiated the live polymer chains on the barriers and rate constants of the involved reaction steps are investigated theoretically. The probability of secondary reactions (such as chain transfer reactions) at elevated temperatures (> 100°C) is higher than that at lower temperatures. Therefore, understanding of these mechanisms is important for developing more efficient high temperature polymerization processes.

Related publications

  • N. Moghadam, S. Liu, S. Srinivasan, M. C. Grady, M. Soroush, and A. M. Rappe, "Computational study of chain transfer to monomer reactions in high-temperature polymerization of alkyl acrylates", J. Phys. Chem. A 117, 2605-18 (2013). PDF
  • S. Liu, S. Srinivasan, M. C. Grady, M. Soroush, and A. M. Rappe, "Computational Study of Cyclohexanone-Monomer Co-initiation Mechanism in Thermal Homo-polymerization of Methyl Acrylate and Methyl Methacrylate", J. Phys. Chem. A 116, 5337-48 (2012). PDF
  • S. Kim, M. Rutenberg-Schoenberg, and A. M. Rappe, "Kinetics of palladium particles on LiNbO3: an origin of the polarization­dependent catalysis", MRS Proceedings 1397, 12-01 (1-7) (2012). PDF
  • T. Rier, S. Srinivasan, M. Soroush, G. A. Kalfas, M. C. Grady, and A. M. Rappe, "Macroscopic Mechanistic Modeling and Optimization of a Self-Initiated High-Temperature Polymerization Reactor", IEEE, 3071-6 (2011). PDF
  • S. Kim, M. Rutenberg Schoenberg, and A. M. Rappe, "Polarization Dependence of Palladium Deposition on Ferroelectric Lithium Niobate (0001) Surfaces", Phys. Rev. Lett. 107, 076102 (1-5) (2011). PDF Supplementary material PDF
  • S. Srinivasan, M. W. Lee, M. C. Grady, M. Soroush, and A. M. Rappe, "Computational evidence for self-initiation in spontaneous high-temperature polymerization of methyl methacrylate", J. Phys. Chem. A 115, 1125-32 (2011). PDF
  • S. Srinivasan, M. W. Lee, M. C. Grady, M. Soroush, and A. M. Rappe, "Self-Initiation Mechanism in Spontaneous Thermal Polymerization of Ethyl and n-Butyl Acrylate: A Theoretical Study", J. Phys. Chem. A 114, 7975-83 (2010). PDF
  • S. Srinivasan, M. W. Lee, M. C. Grady, M. Soroush, and A. M. Rappe, "Computational Study of the Self-Initiation Mechanism in Thermal Polymerization of Methyl Acrylate", J. Phys. Chem. A 113, 10787-94 (2009). PDF
  • S. E. Mason, E. A. Sokol, V. R. Cooper, and A. M. Rappe, "Spontaneous Formation of Dipolar Metal Nanoclusters", J. Phys. Chem. A 113, 4134-7 (2009). PDF
  • D. Li, M. H. Zhao, J. Garra, A. M. Kolpak, A. M. Rappe, D. A. Bonnell, and J. M. Vohs, "Direct in situ determination of the polarization dependence of physisorption on ferroelectric surfaces," Nat. Mat. 7 473-7 (2008). PDF
  • S. E. Mason, I. Grinberg, and A. M. Rappe, "Orbital-specific Analysis of CO Chemisorption on Transition-Metal Surfaces", J. Phys. Chem. C 112, 1963-6 (2008). PDF
  • A. M. Kolpak, I. Grinberg, and A. M. Rappe, "Polarization effects on the surface chemistry of PbTiO3-supported Pt films", Phys. Rev. Lett. 98 166101 (1-4) (2007). PDF
  • U. G. Singh, J. Li, J. W. Bennett, A. M. Rappe, R. Seshadri, and S. L. Scott, "A Pd-doped perovskite catalyst, BaCe1-xPdxO3-δ for CO Oxidation", J. Catal. 249, 349-58 (2007). PDF
  • J. Li, U. G. Singh, J. W. Bennett, K. Page, J. Weaver, J.-P. Zhang, T. Proffen, A. M. Rappe, S. Scott, and R. Seshadri, "BaCe1-xPdxO3-δ (0≤x≤ 0.1): Redox controlled ingress and egress of palladium in a perovskite", Chem. Mater. 19, 1418-26 (2007). PDF
  • V. R. Cooper, A. M. Kolpak, Y. Yourdshahyan, and A. M. Rappe, "Oxide-supported metal thin-film catalysts: the how and why?", Nanotechnology in catalysis, Vol. 3, B. Zhou, ed., Springer-Verlag New York, pp. 13-21 (2006). PDF
  • S. E. Mason, I. Grinberg and A. M. Rappe, "Adsorbate-adsorbate interactions and chemisorption at different coverages studied by accurate ab initio calculations: CO on transition metal surfaces", J. Phys. Chem. B 110, 3816-22 (2006). PDF
  • V. R. Cooper, A. M. Kolpak, Y. Yourdshahyan, and A. M. Rappe, "Supported metal electronic structure: implications for molecular adsorption", Phys. Rev. B Rapid Comm. 72, 081409(R) (1-4) (2005). Selected for the Virtual Journal of Nanoscale Science and Technology, September 12, 2005 issue. PDF
  • M.-L. Bocquet, A. M. Rappe, and H.-L. Dai, "A density functional theory study of adsorbate-induced work function change and binding energy: Olefins on Ag(111)", Molecular Physics 103, 883-90 (2005). PDF
  • Y. Yourdshahyan, V. R. Cooper, A. M. Kolpak, and A. M. Rappe, "Catalytic behavior at the nanoscale: CO adsorption on Al2O3-supported Pt clusters", Proc. SPIE 5223, 223-31 (2004). PDF
  • S. E. Mason, I. Grinberg, and A. M. Rappe, " First-principles extrapolation method for accurate CO adsorption energies on metal surfaces", Phys. Rev. B Rapid Comm. 69, 161401R (1-4) (2004). PDF
  • E. J. Walter and A. M. Rappe, "Coadsorption of methyl radicals and oxygen on Rh (111)", Surf. Sci. 549, 265-72 (2004). PDF
  • R. P. Kauffman and A. M. Rappe, ``Vacancies below the (111) surface of Pd'', Phys. Rev. B 67, 085403 (1-6) (2003). PDF
  • Y. Yourdshahyan and A. M. Rappe, ``Structure and energetics of alkanethiol adsorption on the Au(111) surface'', J. Chem. Phys. 117, 825-33 (2002). PDF
  • I. Grinberg, Y. Yourdshahyan, and A. M. Rappe, ``CO on Pt(111) puzzle: A possible solution'', J. Chem. Phys. 117, 2264-2270 (2002). PDF
  • X. Lin, N. J. Ramer, A. M. Rappe, K. Hass, W. F. Schneider, and B. L. Trout, ``Effect of Particle Size on the Adsorption of O and S Atoms on Pt: a Density Functional Study'', J. Phys. Chem. B 105, 7739-7747 (2001). PDF
  • E. J. Walter, S. P. Lewis, and A. M. Rappe, ``First-principles study of carbon monoxide adsorption on zirconia-supported copper'', Surf. Sci. 495, 44-50 (2001). PDF
  • Y. Yourdshahyan, H. K. Zhang, and A. M. Rappe, ``$n$-Alkyl thiol group interactions with the Au (111) surface'', Phys. Rev. B Rapid Comm. 081405 (1-4) (2001). PDF
  • E. J. Walter, S. P. Lewis, and A. M. Rappe, ``Investigation of chemisorbed molecular states for oxygen on rhodium (111)'', J. Chem. Phys. 113, 4388-4391 (2000). PDF
  • E. J. Walter and A. M. Rappe, ``Accurate and efficient determination of chemisorption energies using pseudopotentials,'' Surf. Sci. 427-428, 11-14 (1999). PDF
  • S. P. Lewis and A. M. Rappe, ``Structural and vibrational properties of carbon monoxide adlayers on the copper (001) surface'', J. Chem. Phys. 110, 4619-4633 (1999). PDF
  • E. J. Walter, S. P. Lewis, and A. M. Rappe, "Internally consistent predictions of surface structural relaxations", Laser Techniques for Surface Science III, Proc. SPIE 3272, 196-200 (1998). PDF
  • S. P. Lewis, M. V. Pykhtin, E. J. Mele, and A. M. Rappe, "Continuum elastic theory of adsorbate vibrational relaxation", J. Chem. Phys. 108, 1157-61 (1998). PDF
  • S. P. Lewis and A. M. Rappe, "Bonding and vibrational properties of CO-adsorbed copper", Symposium Mater. Res. Soc. 391-9 (1996). PDF PDF
  • S. P. Lewis and A. M. Rappe, "Substrate-adsorbate coupling in CO-adsorbed copper", Phys. Rev. Lett. 77, 5241-4 (1996). PDF
  • S. P. Lewis and A. M. Rappe, "Quantum-mechanical investigation of bonding and vibrational properties of CO-adsorbed copper", Proc. SPIE 2547, 227-39 (1995). PDF
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