Lithography-free silicon micro-pillars as catalyst supports for microfabricated fuel cell applications

Abstract

Submicron-scale silicon pillars produced by a novel lithography-free process were demonstrated to be excellent catalyst support structures for the depositions of Pt and Pt–Ru in liquid-fed microfabricated fuel cell applications. Operating conditions of the polysilicon CVD process and the etching duration were controlled in order to form the pillars with the desired dimension. The pillar-supported catalysts obtained from the electrochemical deposition exhibit good mass activity (0.220 A/mg at 0.5 V (vs. Ag/AgCl) for Pt–Ru) towards methanol oxidation compared to the carbon-supported counterparts. Moreover, the development of this pillar-based support structure is a step closer to the realization of the monolithic integration of a Si-based microfabricated fuel cell.