Microkinetic Modeling of the Transient CO2 Methanation with DFT‐Based Uncertainties in a Berty Reactor. Issue 18 (25th August 2022)

• Record Type: Journal Article
• Authors: Kreitz, Bjarne; Wehinger, Gregor D.; Goldsmith, C. Franklin; Turek, Thomas
• Is Part Of: ChemCatChem. Volume 14:Issue 18(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-25
• Subjects: Methanation -- Dynamic operation -- Microkinetic modeling -- Kinetics -- Heterogeneous catalysis; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.202200570
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: The transient operation of methanation reactors can become desirable when coupled with fluctuating renewable energies in Power‐to‐Gas scenarios, which requires suitable kinetic approaches that can describe the transient catalytic phenomena. A combined experimental and theoretical investigation of the transient CO2 methanation is conducted using concentration forcing to derive a suitable microkinetic model. Methanation experiments are performed with a Ni/SiO2 catalyst in a Berty‐type reactor at industrially relevant conditions. The microkinetics are based on previous work and were automatically constructed for the Ni(111) facet using the Reaction Mechanism Generator. A feasible set of energetic parameters of the microkinetic models was identified in a theory‐constrained optimization procedure within the DFT uncertainty space that can accurately reproduce the experimental results on a first‐principles basis. The microkinetic model unravels that the formation of H2 O* and CH3 * control the activity and selectivity of Ni(111) under the investigated conditions. Abstract : A microkinetic model for the CO2 methanation on Ni(111) is derived from first‐principles considering the uncertainty in the DFT method. Through an efficient theory‐constrained optimization procedure, it was possible to find a feasible set of parameters that can qualitatively and quantitatively predict transient experiments on a Ni/SiO2 catalyst at industrially relevant conditions.