Pd thickness optimization on silicate sheets for improving catalytic activity

Abstract

Maximizing surface-to-body ratio demands ever smaller metallic palladium (Pd) nanoparticles for catalytic applications. The quest for miniaturization is now reaching the single-atom limit. However, if the supported Pd is below a critical size, the Pd hybridization with the supporting material can detrimentally reduce the labile electrons that facilitate the catalytic reactions. Thus, the smallest attainable size, i.e., single-atom Pd, may not offer the best efficiency. Here, it is demonstrated that Pd with at least six atomic layers (or thickness of approximate to 1 nm) on the silicate sheets, synthesized via the partial exfoliation of a layered silicate, exhibits a metallic-like electronic property, yielding an excellent catalytic activity (e.g., turnover frequency) for dehydrogenating formic acid higher than both isotropic Pd nanoparticles and single-atom Pd.