Highly stable ternary tin–palladium–platinum catalysts supported on hydrogenated TiO2nanotube 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 m² g⁻¹_Pt+Pd, which is 1.3 folds than the commercial JM Pt/C (104 m² 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.