(469h) Identifying Reaction Pathways for the Sabatier Reaction on Stepped Metal (211) Surfaces

Devyani Sharma¹, Karsten Reuter², and Mie Andersen²

¹Department of Chemical Engineering, Indian Institute of Technology Madras, India

²Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universität München, Germany

Abstract

The catalytic conversion of carbon dioxide and hydrogen to form methane and water (the Sabatier reaction) was first discovered by the French scientist Paul Sabatier in the 1910s. In recent years, such chemical recycling of CO₂ has received renewed interest due to the adverse effects on our climate from rising levels of CO₂ in the atmosphere and the need for a clean and sustainable production of fuels and chemicals [1].

The aim of the present work is to identify trends in the preferred CO₂ dissociation pathways over the stepped (211) surfaces of Cu, Rh, Ru, Pd, Pt and Re. We use density functional theory (DFT) with the dispersion-corrected BEEF-vdW functional [2] in order to accurately capture the weak interaction of CO₂ and related intermediates with metal surfaces. Transition states are identified using the nudged elastic band (NEB) method.

We compare pathways relying on the direct CO₂ dissociation as well as hydrogen-assisted pathways involving the COOH [3] or HCOO (formate) intermediate [4]. Since many of the more active catalysts are expected to exhibit a high coverage of CO under reactions conditions, which could substantially influence the reaction barriers and preferred pathways [5], we also consider the effect of lateral interactions on the CO₂ dissociation trends in realistic, high-coverage structures. The obtained DFT data are used to construct a microkinetic model to evaluate the preferred pathways, important intermediates and catalytic activities over the series of transition metal catalysts.

References:

[1] Wang, Wei, et al. Chemical Society Reviews 40.7 (2011): 3703-3727.

[2] Wellendorff, Jess, et al. Physical Review B 85.23 (2012): 235149.

[3] Dietz, et al. The Journal of Physical Chemistry C 119.9 (2015): 4959-4966.

[4] Cao, Dong-Bo, et al. Surface Science 603.19 (2009): 2991-2998.

[5] Lausche, Adam C., et al. Journal of catalysis 307 (2013): 275-282.