Templated synthesis of atomically-thin Ag nanocrystal catalysts in the interstitial space of a layered silicate

Abstract

Enclosing functional nanoparticles in stable inorganic supports is important for generating ultra-stable catalytic active sites with good performance and material utilization efficiency. Here we describe a simple method to synthesize ultra-thin Ag nanocrystals with dimensions that are defined by the ∼1.4 nm 2D interlayer separating a layered silicate nanostructure. We call the particles “nanoplates” because they are <1.4 nm thick in one direction and their in-plane dimensions are defined by reaction time. The layered silicate is pillared with dialkylurea, which serves both as a reducing agent for the Ag precursor and immobilizes the Ag nanoplates in the interstitial nanospace. The supported Ag nanoplates showed catalytic activity for hydrolysis of NH₃BH₃ and generation of H₂ at room temperature. These supported Ag nanocatalysts had performance much higher than spherical Ag nanoparticles. They, moreover, had performance and stability comparable to costly supported Pt nanoparticles.