Stable single-atom platinum catalyst trapped in carbon onion graphitic shells for improved chemoselective hydrogenation of nitroarenes

Abstract

Supported platinum (Pt) catalysts present excellent chemoselectivity for a variety of hydrogenation reactions. Minimizing the use of such expensive catalysts while retaining their catalytic activities has been one of the most challenging topics in recent years. The construction of well dispersed, stable Pt single atom catalysts both increases the density of catalytically active sites while reducing Pt usage. Here we report the synthesis of Pt single atoms trapped in carbon onion graphitic shells by arc-discharge in aqueous solution. Such graphitic shells not only limit the chemical/thermal coarsening of Pt single atoms, but also enhance the conductivity for accelerating the penetration and exchange of ions and electrons during the catalytic process. Experimental results demonstrate that the Pt single atom catalysts show superior performance and no detectable loss of activity and selectivity over 10 cycles (both remain >99%) for the hydrogenation of p-chloronitrobenzene. This novel atomically dispersed form of Pt catalyst is indicative of a new avenue towards efficient synthesis of single atom catalysts with improved performance.