Quantum effects in thermal reaction rates at metal surfaces

Accurate description of elementary steps of chemical reactions at surfaces is a long-standing challenge because of the lack of reliable experimental measurements of the corresponding rate constants, which also makes it impossible to rigorously validate theoretical estimates. Even for reactions as simple as thermal recombination of hydrogen atoms on platinum surfaces, previous experimental rate constants have only been obtained with large uncertainties. Using velocity-resolved kinetics and ion imaging–based calibration of absolute molecular beam fluxes, Borodin et al. managed to overcome established experimental difficulties and report unprecedentedly accurate rate constants for this reaction over a wide temperature range. They also demonstrate a parameter-free model that quantitatively reproduces the experiment, opening up new vistas for the growing field of computational heterogeneous catalysi