Rules of chemical promotion

The recently established rules of electrochemical promotion of catalysis (EPOC or NEMCA effect) are compared with all combined promotional and kinetic studies published in the Journal of Catalysis and other journals during the last 10 years. In all 33 cases surveyed the promotional rules are found to be in agreement with experiment. These rules enable one to predict the desired type of promoter on the basis of the unpromoted reaction kinetics or the type of kinetics on the basis of the rate dependence on promoter coverage. This validation of the electrochemical promotion rules by the classical promotion literature underlines the functional similarity and only operational difference of electrochemical and classical promotion. It also shows that electrostatic interactions in the double layer formed at the catalyst–gas interface are a key element of promotion in catalysis.