Discovery of New Nanocatalysts by HighThroughput Computational Screening

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Discovery of New Nanocatalystsby High-Throughput
Computational Screening
RusNanoForum
Moscow, October 7, 2009

• Claus Hviid Christensen

Claus J. H. Jacobsen until 2003
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From the Macroscopic to the Nanoscopic World
Active surface structure
Catalytic reactor
Catalyst pellets
Porous catalyst structure
Christensen, Nørskov, J. Phys. Chem. 128 (2008)
182503 Nørskov, Rossmeisl, Bligaard, Christensen,
Nature Chem. 1 (2009) 63
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Towards Computational Screening

• A New Approach for Catalyst Discovery
• Ammonia Synthesis
• Identifying Descriptors for Catalytic Activity
• Volcano Curves and the Interpolation Concept
• Methanation
• Pareto-Optimal Catalysts
• Selective Hydrogenation of Acetylene
• Descriptors for Catalyst Selectivity

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Catalytic Ammonia Synthesis
N2 3 H2 ? 2 NH3

• Ammonia synthesis necessary for sustaining
• global population above 4 billion
• N2 dissociation rate-determining
• gt250.000 catalysts tested experimentally

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Catalytic Ammonia Synthesis

• Structure of active site

In situ HRTEM
Hansen, Wagner, Hansen, Dahl, Topsøe, Jacobsen,
Science 294 (2001) 1508
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Density Functional Calculations

• Self-consistent GGA (RPBE)
• Perdew, Burke, Ernzerhof , PRL 80, 891 (1998)
• Hammer, Hansen, Nørskov, PRB 59, 7413 (1999)
• Ultra-soft pseudopotentials, plane wave basis
• Vanderbilt, PRB 41, 7892 (1996)
• Slab geometry
• Complete structural relaxation
• Iterative method for finding transition states
• Mills, Jonsson, Schenter Surf. Sci. 324, 305
  (1995)

http//www.fysik.dtu.dk/CAMPOS
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Ammonia Synthesis from First Principles
Honkala, Remediakis, Logadottir, Nørskov,
Hellman, Dahl, Carlsson, Christensen, Science 307
(2005) 555.
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BEP Relation for N2 Dissociation
Logadottir, Rod, Nørskov, Hammer, Dahl, Jacobsen,
J. Catal. 2001, 197, 229
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Potential Energy Diagrams
Dahl, Jacobsen, Logadottir, Nørskov, Appl. Catal.
A 222 (2001) 19
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Volcano Curves
450C 100 bar 31 H2/N2
0.01 NH3
Ru
0.1 NH3
Os
Fe
1 NH3
Co
10 NH3
Mo
Ni
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Interpolation in The Periodic Table
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Design of New Alloy (Nitride) Catalysts
Co3Mo3N
Ru
Fe
Jacobsen, C. J. H., Chem. Commun. (2000) 1057
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Methanation
CO 3 H2 ? CH4 H2O

• Purification of syngas for ammonia synthesis
• Industrial catalyst Ni/alumina
• High-throughput experimental screening
• recently conducted

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Pareto-Optimal Methanation Catalysts
Andersson, Bligaard, Greeley, Kustov,
Christensen, Nørskov, J. Catal. 239 (2006) 501.
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Experimental Activity of Fe/Ni Alloy Catalysts
Christensen et al., Patent Pending Christensen
et al., Appl. Catal. A. (2007).
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Several new catalysts for methanation identified
But the Ni-Fe system not found!
? Complementarity between experimental and
theoretical screening
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Selective Acetylene Hydrogenation
HCCH H2 ? H2CCH2
H2CCH2 H2 ? H3CCH3

• Purification of ethylene from steam crackers
• Industrial catalysts PdAg/alumina

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Selective Acetylene Hydrogenation
Studt, Abild-Pedersen, Zn, Bligaard, Christensen,
Nørskov, Science 320 (2008) 1320
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Selective Acetylene Hydrogenation
10 wt metal on a 250-500 mesh MgAl2O4
spinel 1.33 ethylene, 0.0667 acetylene, 0.67
hydrogen
Studt, Abild-Pedersen, Zn, Bligaard, Christensen,
Nørskov, Science 320 (2008) 1320
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Towards Computational Screening

• A New Approach for Catalyst Discovery
• Ammonia Synthesis
• Identifying Descriptors for Catalytic Activity
• Volcano Curves and the Interpolation Concept
• Methanation
• Pareto-Optimal Catalysts
• Selective Hydrogenation of Acetylene
• Descriptors for Catalyst Selectivity

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Acknowledgements

• Thank you for your attention
• You can receive the presentation from
• chc_at_topsoe.dk