Microfluidic-enabled control of ethanol oxidation catalyst synthesis by separating heterogeneous nucleation and growth processes

The rational design of inexpensive and highly efficient electrocatalysts for ethanol oxidation reaction (EOR) is crucial for direct ethanol fuel cells. In this study, a series of carbon -supported PtCu electrocatalysts with varying Pt/Cu ratios were synthesized using a microfluidic system. This system enabled the separation of heterogeneous nucleation and nanocrystal growth based on segmental thermal induction. Heterogeneous nucleation occurred at the low -temperature zone, which resulted in uniform loading, while the enhancement of solvent reducibility in the high -temperature region enabled the control of the PtCu nanoparticle composition. The synthesized PtCu/C electrocatalyst, with Cu content adjustable from 17% to 38%, exhibited high crystallinity and homogeneous dispersion, with an average particle size of 3.9 nm. These advantageous physical properties endowed the PtCu/C electrocatalysts with significantly enhanced electrocatalytic performance for EOR compared with commercial Pt/ C catalysts. The development of this method presents a novel approach for the controlled preparation of supported catalysts.