Effect of Ti sublayer on the ORR catalytic efficiency of dc magnetron sputtered thin Pt films

摘要

A series of thin Pt films were deposited by dc magnetron sputtering directly on a commercial hydrophobic carbon paper substrate having a thin microporous Vulcan-XC72 layer or upon a thin Ti sublayer sputtered on the top of the microporous carbon film. The electrocatalytic properties of the sputtered Pt films toward the oxygen reduction reaction were investigated in 0.5 M H_2SO_4 solution and in a hydrogen PEM fuel cell. The catalyst with ultralow Pt loading of 22 μg cm~(-2) deposited on a 33 A thick Ti sublayer is robust, mechanically stable, possesses highly developed surface area and improved catalytic efficiency. Its performance as a MEA cathode in a single hydrogen PEM fuel cell (577 mA cm~(-2) at 0.4 V cell voltages and a maximum power of 0.954 W) proved to be much superior compared to that of MEA with the same cathode Pt loading but without Ti sublayer (173 mA cm~(-2) at 0.4 V, 0.231 W, respectively).