Towards rational catalyst design: Boosting rapid prediction of transition-metal activity by improved scaling relations
Understanding scaling relations of adsorption energies and activation energies greatly facilitate the computational catalyst design. To reduce the computational cost and guarantee the efficiency, improved scaling relations are advocated in this study to fast acquire energetics for transition metal surface reactions, further to rapidly and effectively map the activity of transition-metal catalysts. The overall catalytic activity for surface reactions between C, H and O containing species can be related backed to the adsorption energies, using C, H and O binding energies as descriptors via the improved scaling relations. The UBI-QEP (unity bond index-quadratic exponential potential) method, one of scaling relations to estimate adsorption energies from descriptors, is significantly improved by taking into account the changes in A-B bond index during the adsorption and the molecular structure of adsorbed species using density functional theory (DFT) data as a benchmark. The improved UBI-QEP approach can satisfactorily predict the DFT (BEEF-vdW) and experimental adsorption energies. DFT calculations with BEEF-vdW functional are also employed for establishing the BEP (Brønsted-Evans-Polanyi) relationships, scaling relations to correlate reaction heats with activation energies, for C-H, C-O, C-C, O-H bond cleavages and recombination. The capability of improved UBI-QEP + BEP approach is tested as a generic framework to map the activity trend for steam methane reforming (a probe reaction) through microkinetic modeling. The results demonstrate that our approach reduces the computational cost in six orders of magnitude, while maintains a reasonable degree of accuracy as compared to the DFT (BEEF-vdW) and experiments.