You are here
Theoretical/Computational Tools for Energy-Relevant Catalysis
Principal Investigators: James Evans, Mark Gordon
This project will develop new strategies for and integrated combinations of electronic structure analysis and statistical mechanical, coarse-grained, and multi-scale modeling approaches to treat energy-relevant heterogeneous catalytic systems. Currently, there is a lack of effective molecular-level modeling for overall catalytic reaction processes and a critical need to incorporate high-level energetics for predictivity. Essential to these efforts will be the development of novel new approaches in not only theoretical chemistry and materials science (BES), but also computational science and applied mathematics (ASCR). Applications motivating the work include analysis of catalysis in mesoporous oxides and catalysis on metal surfaces and supported metal nanoclusters.
This research is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences and by the U.S. Department of Energy, Office of Advanced Scientific Computing Research through the Ames Laboratory. The Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358
A new theory shows that reactivity at catalytic sites inside narrow pores is controlled by how molecules move at the pore openings. Like cars approaching a single lane tunnel from which other cars are emerging, the movement of molecules depends on their distance into the pore; near the ends of the pores, exchange is rapid compared to further into the pores. Dynamics at the openings of these pores controls the penetration of reactants and thus overall conversion to products.
Researchers can now analyze how reactions proceed inside porous nanoparticles where the molecules are in such narrow channels that they cannot pass each other. Catalysis within these confined conditions is significantly impacted by restricted transport. Typical pore diameters are in the range of 2 - 10 nm, and with catalyst molecules attached inside them, the pore diameter can be reduced below 2 nm. Traditional computational tools do not capture the evolution of concentrations inside pores so narrow that reactants and products cannot pass each other.
Findlater A.D.; Zahariev F.; Gordon M.S. Combined Fragment Molecular Orbital Cluster in Molecule Approach to Massively Parallel Electron Correlation Calculations for Large Systems. Journal of Physical Chemistry A 2015 119, 3587-3593. Abstract
Liu D.J.; Evans J.W. Transitions between strongly correlated and random steady-states for catalytic CO-oxidation on surfaces at high-pressure. Journal of Chemical Physics 2015 142, 134703. Abstract
Ghandi K.; Findlater A.D.; Mahimwalla Z.; MacNeil C.S.; Awoonor-Williams E.; Zahariev F.; Gordon M.S. Ultra-fast electron capture by electrosterically-stabilized gold nanoparticles. Nanoscale 2015 7, 11545-11551. Abstract
Liu D.J.; Evans J.W. Dissociative adsorption of O-2 on unreconstructed metal (100) surfaces: Pathways, energetics, and sticking kinetics. Physical Review B 2014 89, 205406. Abstract
Dieterich J.M.; Krisiloff D.B.; Gaenko A.; Libisch F.; Windus T.L.; Gordon M.S.; Carter E.A. Shared-memory parallelization of a local correlation multi-reference CI program. Computer Physics Communications 2014 185, 3175-3188. Abstract
Liu D.J.; Evans J.W. Realistic multisite lattice-gas modeling and KMC simulation of catalytic surface reactions: Kinetics and multiscale spatial behavior for CO-oxidation on metal (100) surfaces. Progress in Surface Science 2013 88, 393-521. Abstract