In-situ synthesized TiC@CNT as high-performance catalysts for oxygen reduction reaction

Abstract

Developing low cost and high performance catalyst for oxygen reduction reaction (ORR) is a critical factor for novel energy sources. In this paper, we adopt carbon nanotube (CNT) as carbon source to synthesize titanium carbide (TiC). With the catalysis of iodine and sodium, the CNT react with titanium particles and in-situ synthesizes co-axial TiC@carbon nanotube (TiC@CNT). The co-axial structure is confirmed by X-ray diffraction, scanning electron microscope, X-ray photo-electron spectroscopy and transmission electron microscopy tests. The electrocatalytic performances for ORR are investigated by cyclic voltammetry, Tafel, linear sweeping voltammetry, rotating disc electrode and rotating ring disc electrode methods. Results show that the TiC@CNT has high catalytic performance for ORR in both alkaline and acidic electrolytes. The ORR mainly happens through 4-electron pathway. The CNT plays the role of electron conductor and the TiC plays the role of active center for ORR. The high catalytic activity should be attributed to the synergistic effect of CNT and TiC.