Recent advances in single atom catalysis have sparked interest in their use as low-cost and high efficiency catalysts in a wide variety of reactions. One such reaction that has been heavily studied with single atom catalysts is the water gas shift reaction. In addition, water participates in a rich variety of other industrially important catalytic processes, such as steam reforming reactions. However, much debate surrounds the structure and activity of single atoms toward water gas shift chemistry. By taking a model study approach, we determine the influence of atomically dispersed Pt atoms on the activation of water. Using a thin film Cu2O/Cu(1 1 1) support, water activation is probed via isotopic scrambling temperature programed desorption experiments. We determine that the presence of supported single Pt atoms on the thin Cu2O film will facilitate the low-temperature activation of water. Theory offers a viable water scrambling pathway on the supported Pt atoms, detailing the dynamic relationship between water, the Pt atom, and the support. The results reveal that single Pt atoms are capable of O-H bond activation when water interacts with such a catalyst. (C) 2018 Elsevier Inc. All rights reserved.