AVS 53rd International Symposium
    Surface Science Monday Sessions
       Session SS1-MoM

Paper SS1-MoM2
Toward Computational Screening in Heterogeneous Catalysis: Pareto-Optimal Methanation Catalysts

Monday, November 13, 2006, 8:20 am, Room 2002

Session: Catalytic Chemistry of Hydrocarbons
Presenter: M.P. Andersson, Technical University of Denmark
Authors: M.P. Andersson, Technical University of Denmark
T. Bligaard, Technical University of Denmark
A. Kustov, Technical University of Denmark
K.E. Larsen, Technical University of Denmark
J. Greeley, Technical University of Denmark
T. Johannessen, Technical University of Denmark
C.H. Christensen, Technical University of Denmark
J.K. Norskov, Technical University of Denmark
Correspondent: Click to Email
In this work we make the first step towards a computational screening for catalyst materials based on density functional theory and apply it to find new metal alloy materials for the methanation reaction (CO + 3H@sub 2@ -> CH@sub 4@ + H@sub 2@O), see e.g.@footnote 1@ We do so by using the following procedure: First we establish a descriptor for the reaction, which we then use to screen new alloy materials for high activity. The most interesting candidates are investigated in more detail using density functional theory and their methanation activities are finally tested experimentally. The descriptor is chosen based on the fact that there are two key parameters for methanation: The CO dissociation barrier and the stability of the intermediates C and O. These two properties are furthermore linearly related in a so-called Brønsted-Evans-Polanyi (BEP) relation@footnote 3@ and we are able to reduce them to a single descriptor, the dissociation energy of CO, which gives the expected volcano shaped curve. We have screened 117 binary alloys by estimating activity and price from interpolation of the bulk composition. We make a simultaneous optimization of both activity and price via a pareto plot,@footnote 2@ and we predict FeNi and FeNi@sub 3@ alloys to be both more active and cheaper than pure Ni catalysts (the current industrial catalysts). Full density functional theory calculations confirm the results of the interpolation scheme. Finally we have investigated the activity towards methanation for Fe-Ni alloys and have found that alloys with 50-75% Ni have an activity better thatn pure Ni by about a factor of two to three. @FootnoteText@ @footnote 1@Sehested J, Dahl S, Jacobsen J, et.al. J. Phys. Chem. B 109, 2432-2438 (2005)@footnote 2@Bligaard T, Johannesson GH, Ruban AV, et.al. Appl. Phys. Lett. 83, 4527-4529 (2003).@footnote 3@Nørskov JK, Bligaard T, Logadottir A. et.al. J. Catal. 209, 275-278 (2002).