Highly stable ternary tin–palladium–platinum catalysts supported on hydrogenated TiO2 nanotube arrays for fuel cells

Abstract

Herein the Pt nanocrystals were synthesized by a high-pressure methanol reduction method onto the hydrogenated TiO2 nanotube arrays pre-treated by Sn/Pd. Then Sn/Pd/Pt ternary catalysts were fabricated by hydrogen treatment. The composite catalysts with a diameter of about 18 nm were located uniformly at the inner nanotubes. The novel catalyst combined with hydrogenated TiO2 nanotube arrays exhibits excellent electro-catalytic activity and high durability. The electrochemical performance of the catalysts after 18,000 potential cycles between 0 and 1.2 V vs. RHE could reach the maximum, and the electrochemical surface area of the catalyst at 18,000 cycles is about 136 m(2) g(-1)Pt+Pd, which is 1.3 folds than the commercial JM Pt/C (104 m(2) g(-1)Pt). Furthermore, there is little decrease in the electrochemical surface area for the catalyst after additional 7300 potential cycles (total 24,300 cycles). In a full cell testing, the fabricated novel electrode with extra-low Pt loading (0.043 mg cm(-2)) generated power as 1.21 kW g(-1)Pt when it is used as the cathode in a fuel cell.