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Rational design of novel efficient catalysts requires an accurate quantitative understanding of the mechanism, energetics and kinetics of the catalytic cycle. In our approach1,2,3, we address this by using density functional based molecular dynamics (DFT-MD) methods, taking the role of temperature and solvent explicitly into account. We demonstrate how important types of catalytic systems this can provide fundamental novel insight.
Metal-based molecular catalyst play an important role in large range of applications. Examples are 1) asymmetric hydrogenation converting ketones in chiral alcohols (see figure), and 2) reversible hydrogenation/dehydrogenation of CO2/MeOH, that play a central role in establishing a hydrogen economy with MeOH as the primary energy carrier.
For prototype models of these two catalytic conversions, we show how solvent water molecules play an active role by participating via hydrogen bonding and mediating proton- transfer processes. This yields a picture of the free-energy profile and reaction mechanism that can be fundamentally different from that predicted by gas-phase calculations without explicit solvent.
References
[1] J.-W. Handgraaf and E.J. Meijer, J. Am. Chem. Soc. 129 (2007) 3099;
[2] A. Pavlova and E.J. Meijer, ACS Catal. 6, (2016) 5350.
[3] V. Sinha, N. Govindarajan, B. de Bruin, E.J. Meijer, ACS Catal., accepted (2018), doi: 10.1021/acscatal.8b01177
Sponsored by the Mellichamp Academic Initiative in Sustainability