Computer-Generated Kinetics for Coupled Heterogeneous/Homogeneous Systems: A Case Study in Catalytic Combustion of Methane on Platinum

The automatic microkinetic mechanism generator for heterogeneous catalysis, RMG-Cat, has been extensively updated. Density functional theory calculations were performed for 69 adsorbates on Pt(111), and the resulting thermodynamic properties were added to RMG-Cat. The thermo database is significantly more accurate; it includes nitrogen-containing adsorbates for the first time as well as better capabilities for predicting the thermochemistry of novel adsorbates. Additionally, RMG-Cat can now simultaneously pursue a mechanism expansion both on the surface and in the gas phase. This heterogeneous/homogeneously coupled capability is tested on the catalytic combustion of methane on platinum. The results confirm that under some conditions the catalyst is capable of inducing thermal ignition in the gas phase.