Quo vadis multiscale modeling in reaction engineering? – A perspective

Detailed Microkinetics for the Oxidation of Exhaust Gas Emissions through Automated Mechanism Generation

“…Although the incorporation of surface oxidation can be done in a somewhat ad hoc manner by adjusting the active surface area, 9,74,93 a more rigorous and predictive description can only be achieved with ab initio computations. 94 Figure S11 shows that the microkinetic model can reproduce the experimental results by only adjusting the active surface area. Additionally, the deviation can also be caused by the assumption that only the static Pt(111) facet is the active site, which is a strong simplification of the complex multifaceted Pt crystals on the support that can also transform dynamically during the experiment depending on the local gas atmosphere.…”

“…32,33,88 To reduce the uncertainty margin further, it is suggested to perform transition state calculations for the most important pathways to refine the microkinetics, where the methodology proposed herein can serve as a hierarchical refinement procedure. 94 The microkinetic model parameters were fitted within their uncertainty range to a limited set of experiments. For a better verification of the developed microkinetics as well as the role of Pt(111), it will also be necessary to compare simulations with additional experiments such as reaction order measurements.…”

Detailed microkinetics for the oxidation of exhaust gas emissions through automated mechanism generation

“…Although, the incorporation of surface oxidation can be done in a somewhat ad hoc manner by adjusting the active surface area, 9,73,92 a more rigorous and predictive description can only be achieved with ab-initio computations. 93 Figure S11 shows that the microkinetic model can reproduce the experimental results by only adjusting the active surface area. Additionally, the deviation can also be caused by the assumption that only the static Pt(111) facet is the active site, which is a strong simplification of the complex multifaceted Pt crystals on the support that can also transform dynamically during the experiment depending on the local gas atmosphere.…”

“…32,87 To reduce the uncertainty margin further, it is suggested to perform transition state calculations for the most important pathways to refine the microkinetics, where the methodology proposed herein can serve as a hierarchical refinement procedure. 93 Additionally, other facets can and do contribute to the conversion of the pollutants and the entire multifaceted nature of the crystals on the support need to be considered in the microkinetic model. 80,94,95 In principle, RMG can construct microkinetic models for all possible Pt facets if accurate thermochemical tables and BEP relations are provided.…”

Microkinetic Modeling of the Transient CO2 Methanation with DFT‐Based Uncertainties in a Berty Reactor

“…In fact, all of the results from the global uncertainty assessment are reasonable. It needs to be stressed that a crucial step to be more conclusive about the activity and selectivity of specific metal facets for certain reactions is to actually reduce the error bar of the computed DFT energies to enable a more accurate determination of kinetic and thermodynamic parameters [72] . This requires the usage of more accurate DFT methods, such as hybrid functionals or meta‐GGAs, [52,64] which at the time of publication remain computationally too expensive for a system of this size.…”