Metal nanodots formed and supported on chabazite and chabazite-like surfaces

The formation of metal nanoclusters, nanodots and nanowires are the subject of intense current scientific and engineering interest. We report a new, simple and apparently economical technique to generate high concentrations of supported metal nanoparticles using sedimentary chabazite. This technique can be applied particularly well in the generation of relatively uniform supported silver nanodots. High densities of silver nanoparticles on the order of 1–5 nm, centered in the regime of 3 nm, are formed on sedimentary chabazite surfaces by the assemblage of exchanged silver cations thermally reduced to metal under a wide range of conditions including heating in air. Twenty (20) weight percent or more of a zeolite nanosilver composite material may be composed of these supported silver nanoparticles. Semi-synthetic, aluminum enriched chabazite allows the preparation of metal nanoparticles at even higher levels of concentration, up to 40% or more of the weight of the composite. We know of no other technique that can generate such high concentrations of uniform silver nanoparticles so easily, reproducibly and economically. Preliminary experiments indicate that a range of other metals, such as copper and nickel, may form equivalent chabazite induced and supported nanoparticles under appropriate reducing conditions.