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Heterogeneous catalysis is the branch of catalysis in which the catalyst and the reactants occupy distinct phases, most commonly a solid catalyst exposed to gaseous or liquid reactants, so that the chemical transformation occurs at the interface between the two phases ^[1]. The process proceeds through elementary steps that take place on defined surface sites: reactant molecules adsorb onto the catalyst surface, undergo bond breaking and bond formation while bound to surface atoms, and the products desorb to regenerate the active site ^[2]. Because the reaction is confined to a surface, the activity and selectivity are governed by the geometry and electronic structure of the active sites, the adsorption energies of intermediates, and the morphology and chemical state of the catalyst, rather than by properties of the bulk solid alone ^[1]. Heterogeneous catalysis is distinguished from homogeneous catalysis, in which catalyst and reactants share a single phase, by this phase separation and by the fact that mass transport and adsorption at the interface are integral parts of the overall rate ^[2]. The catalyst itself participates in the reaction cycle but is regenerated at the end of each turnover, so it is not consumed, and the microkinetics of adsorbed intermediates determine the observed conversion and product distribution ^[3].