Graphite carbon enclosed AlN nanoparticles with enhanced methanol-tolerant electrocatalytic properties for oxygen reduction

摘要

The methanol crossover effects and high-cost of Pt based catalysts severely restrict the practical applications of direct methanol fuel cells (DMFCs). In this work, a novel structure of similar to 25 nm AlN nanoparticles with graphite carbon outer coating (AlN@C) was synthesized via a one-step solid-state method with simultaneous nitridation processes and carbon graphitization. AlN@C nanocomposites were exploited as a catalyst of the oxygen reduction reaction (ORR). Benefited from the graphite carbon outer coating, AlN@C exhibits enhanced electrochemical properties (more positive onset potential and higher current density) than pure AlN. Notably, superior methanol-tolerance (a negligible current change after adding 3 M methanol) and excellent durability (91.4 % of the initial current density remained after 10000 s of chronoamperometry test) can be observed. This study provides a feasible approach for developing the applications of traditional ceramic materials towards the ORR catalyst in DMFCs.