Simple, rapid, scalable confined synthesis of ultrafine Pt nanoclusters for fuel cells

Abstract

Small-sized nanoclusters exhibit catalytic activity in electrochemical reactions distinct from the bulk-like properties of nanoparticles 2 nm or larger, yet their surfactant-free synthesis remains a formidable challenge. A scalable microchannel-confined synthesis method enables rapid, controlled formation of 1.12 nm Pt nanoclusters without additional surfactants. Kinetic control achieves a nucleation and growth time of approximately 18.6 s, with heat transfer simulations confirming uniform temperature attainment within 0.5 s. Half-cell and single-cell tests, corroborated by density functional theory (DFT) calculations, demonstrate exceptional performance of these Pt nanoclusters in proton exchange membrane fuel cell (PEMFC), achieving a mass activity 1.9 times that of commercial samples and a rated power density of 1.55 W cm−2. This method can employ multiple capillaries assembled into a capillary bundle to enable parallel experiments, highlighting its scalability and potential to advance hydrogen-electricity conversion technologies.