Using a microfluidic device to synthesize bimetallic nanoparticle catalysts with desired phase and size: An improvement of the nanoparticle-KCl matrix method
With efforts from Hao Chen (DiSalvo), Deli Wang (Abruña) and Joshua Tokuda (Pollack), this research is looking to improve the nanoparticle-KCl matrix method.
A great effort at emc2 has been focused on synthesizing bimetallic nanoparticle (Np) catalysts for oxygen reduction reactions. Recently, we developed a Np-KCl matrix method. Using this method, Nps with the desired intermetallic phase and an average particle size of 4 nm were achieved. In order to further improve the ORR activities, a narrower size distribution of these Np catalysts is needed. As a solution, we propose to develop a microfluidic device, in which, the diffusion of the reducing agent and metal precursor solutions can be controlled precisely during synthesis. It will provide rapid homogenous mixing of the two solutions, which is critical to form a uniform Np-KCl matrix. Thus, a narrower size distribution can be achieved after thermal annealing of these Nps to obtain the desired intermetallic phase. In long term, this method has the potential to be used in bulk synthesis and to allow higher annealing temperatures.