Enhanced catalytic activity on atomically dispersed PtSe two-dimensional layers.

A key challenge in heterogeneous catalysis is to design atomically dispersed catalysts with high surface density, while simultaneously preventing agglomeration and promoting electronic metal-support interaction. Transition metal dichalcogenides (TMDs), such as platinum diselenide (PtSe), offer a promising solution due to their unique structural and electronic properties. This study proposes a catalyst design that utilizes atomically dispersed transition metal species within the topmost layer of TMD as catalytic reaction sites. The substantial presence of surface-exposed Pt species on PtSe and their role as catalytic reaction sites are elucidated using operando ambient-pressure X-ray photoelectron spectroscopy. Moreover, significantly high O coverage on PtSe, achieved by mitigating the exclusive adsorption of carbon monoxide (CO), leads to enhanced CO oxidation performance. The characteristic d-band structure and resulting high O coverage of PtSe are further confirmed with density functional theory calculations. Overall, this study highlights the potential of densely distributed atomic transition metal on TMDs, which allows electronic metal-chalcogen interactions and diverse reaction mechanisms.