Automatically generated model for light alkene combustion

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

“…In conclusion, all estimates have to be taken as approximate since some predicted structures by RMG do not represent the most stable configuration on the potential energy surface, and it is necessary to refine the thermochemistry properties over the course of the mechanism development. 27 The present work is the first study that employs the pre-trained machine learning potential from the Open Catalyst Project 36 to obtain converged adsorbate configurations as an initial guess for the DFT calculation. In order to assess the accuracy of the MLP prediction, we computed the single-point energy of the MLP-relaxed structure with DFT and compared it with the fully DFT relaxed energy.…”

“…Yet, adding more accurate thermochemistry values can cause reaction pathways that were feasible before to become irrelevant and vice versa. This highlights the tremendous importance of an accurate thermochemistry for gas-phase molecules and adsorbates, 27,87 especially if BEP relations are used to estimate the barriers. While for the C 1 chemistry, the reactions are mostly equally split into abstraction and dissociation, a significant overhead of abstraction reactions prevails for the C 2 chemistry.…”

“…Thermophysical properties, principally heats of formation, are highly important in microkinetic modeling, whether it is in the gas phase or on the surface. 24,27,87 When BEP relations are employed to estimate the activation barrier of a reaction, the thermochemistry should be as accurate as possible to avoid the propagation of an estimation error into the barrier, which could affect the entire mechanism.…”

“…RMG is a well-established open-source tool to automatically build comprehensive gas-phase mechanisms for combustion or pyrolysis reactions. [24][25][26][27][28] However, RMG has only recently been used for heterogeneously catalyzed reactions. [29][30][31][32] The publications on the heterogeneous catalysis branch of RMG are focused on demonstrating new features rather than developing a microkinetic model suitable to describe experimental results.…”

Community Reaction Network Reduction for Constructing a Coarse-Grained Representation of Combustion Reaction Mechanisms

“…Recently, Blau et al developed a chemical reaction network for a Li-ion solid electrolyte interphase consisting of more than 6000 species, , and the database generated by this technique was analyzed by species filters, Monte Carlo trajectories, and heuristic analysis of average trajectories to reduce to 18 network species . There have been a number of alternatives for automatic mechanism generation − and fragment-based, virtual-reality direct-molecular-dynamics simulations along with network analysis of mechanisms of combustion reactions. − However, in many situations, the reduced models are still too large to meet the requirement of CFD simulations . Furthermore, processes that play rate-limiting roles or driving reactions may not be the most reactive or least reactive ones, and the interconversion, that is, coupling of reactive species, can be highly temperature-dependent, making it a challenging task in the identification of representative species and reaction steps. , Therefore, mechanism reduction continues to be an active research field, and it is of interest to develop methods that integrate reaction rates and species composition across size and temporal scales.…”