Proton Transfers\nat the Water/Solid Interface of α‑Al<sub>2</sub>O<sub>3</sub>–Supported Ni Clusters under Steam Reforming\nConditions: An AIMD Study

Water in contact with a solid surface under ambient conditions\nis known to have a profound impact on reaction processes. However,\nmany industrial heterogeneous catalytic reactions are operated under\nvery harsh conditions that often involve extreme temperature and pressure\nin which the complexity of the dynamic water/solid interface is greatly\nconcealed. Herein, we use <i>ab initio</i> molecular dynamics\nto uncover the fast transfer of protons at the three-phase interface\nof water steam and an Al<sub>2</sub>O<sub>3</sub>-supported Ni cluster\nunder extremely high temperature conditions for methane steam reforming,\none of the most important industrial processes for hydrogen production.\nThrough experimental and computational studies, we have shown that\nthe facile dissociation of water at the support near the interfacial\nregion is the driving force of proton transfer occurring at the steam/Ni/α-Al<sub>2</sub>O<sub>3</sub> interface. The proton transfer leads to the\nhydroxylation of the Ni cluster and thereby greatly facilitates the\nactivation of the stable CH<sub>4</sub> molecule. This finding is\nessential for understanding proton transfer at high temperatures in\nwater-oxide–supported interfaces with metal catalytic systems\nat the atomic level.