Clean Platinum Nano-Catalyst Made Easy

Platinum is widely used in electrochemical and gas-phase catalysis due to its excellent stability and high activity toward a range of important reactions. Thus, Pt is also often used to benchmark the activity of other catalysts, especially in electrocatalytic processes involving hydrogen and oxygen [1, 2]. The electrochemical behavior of platinum nanoparticles has been of great interest for many research groups working on fuel cells for a long time. Hence, there are many papers reviewing the size and electrochemical properties of platinum nanocatalysts [3, 4, 5, 6, 7]. In those contexts, several methods have been reported for the preparation of monodisperse Pt nanoparticles whose surfaces are essentially free of contaminants. However, these methods are difficult to implement in an engineering laboratory with limited facilities and expertise for wet chemical synthesis. \nWe have developed a synthetic procedure for catalytically active Pt nanoparticles that uses only readily available tools and reagents at high safety level, with the goal of making high-quality control experiments in electrocatalysis as easy as possible. Our procedure is based on reduction of aqueous Pt (IV) salts by ascorbic acid in the presence of a polyacrylate capping agent, which can then be removed using a base treatment and a series of solvent washing steps. \nOur results show that this method produces a high yield (60%) of 3–4 nm particles exhibiting the characteristic features of clean Pt surfaces in cyclic voltammetry that is comparable to commercial nanoscale platinum catalysts. These nanoparticles also perform well in catalyzing hydrogen evolution and oxidation experiments in a 3-electrode system.