Kinetic interpretation of catalytic activity npatterns based on theoretical chemical descriptors

摘要

We introduce descriptors of bond energies calculated at the DFT level for bulk crystalling structures We show the relevance of these descripors for surface bonds infofar as they are well correlated eith experimental heats of adsorption Based on these correlations and combining adapted Brnsted-Evans-Polanyi free energy relationships and simple Langmuir-Hinshelwood rate expressions we show that the trends in experimental activity parrerns across the periodic table can be explained by a single variable the elevant bond energy descriptor We obtain "volcano" curves with strong maxima at bond energies that indicate optimal chemical properties Adtivies of metallic formulations involoving binarg alloys in hydrogenation and hysrogenolysis reactins as well as fo ternary sulfides in hydrogesulfuriation are correctly predicted gy the metal-carbon or metal-sulfur bond energy descriptors calculated for simple structural models Our approach therefore provides useul exploratory guidlines.