By using model catalysts that allow high-spatial-resolution characterization by scanning probe microscopy (SPM), surface science studies have provided insights into elementary reaction processes at the atomic or molecular scale. Our research aims to achieve a detailed understanding of the structural and electronic properties of model catalysts that govern catalytic performance, based on well-defined metal single-crystal surfaces and oxide or carbide layers supported on them. We are interested in the activation and conversion of C–O and C–H bonds in small carbon-containing molecules, with the aim of identifying surface active sites and elucidating reaction mechanisms at the molecular level.

In addition, our group has proposed an approach to modulating the surface free energy of oxide supports by preparing ultrathin oxide films on bulk metal substrates, thereby obtaining thermodynamically stable, isolated metal atoms. Electronic effects at the oxide–metal interface lead to drastic changes in the surface properties of the resulting ultrathin oxide films, such that the surface free energy or chemical potential of the supported single metal atoms becomes comparable to or even lower than that of the supporting ultrathin oxide film. We have successfully applied this methodology to prepare a series of supported single-atom model catalysts.