Scalable One-Pot Synthesis of Yolk–Shell Carbon Nanospheres with Yolk-Supported Pd Nanoparticles for Size-Selective Catalysis

Applications of yolk-shell nanostructures in catalysis are very attractive due to their specific catalytic properties deter-mined by the hollow structures, such as size-selective catalysis. However, synthesis of such size-selective yolk-shell nanocatalysts on a large scale by a simple method is highly challenging. We describe the synthesis of yolk-shell carbon nanospheres with yolk-supported Pd nanoparticles (Pd/C@HCS) by only two simple preparation steps: one-pot hydro-thermal synthesis and pyrolysis. The synthetic processes can easily be scaled up, ~6.8 g of Pd/C@HCS is obtained start-ing from 4 L of solution in hydrothermal step. Pd nanoparticles are formed in the emulsion solution which then in-duce the formation of Pd/polymer-yolk nanocomposites, followed by the encapsulation of the nanocomposites inside of hollow polymer nanospheres to form the yolk-shell structures (Pd/P@HPS). The location of the Pd-nanoparticles in the final catalyst can be controlled by the rate of reduction and nanoparticle form...