High catalytic activity of Ti4O7/CNTs oxygen reduction reaction (ORR) electrocatalysts with excellent circulation and methanol resistance

Electro catalysts play a vital role in facilitating the reaction process in the oxygen reduction reaction (ORR) of fuel cells. In methanol fuel cells, methanol easily penetrates the diaphragm rendering the ORR catalyst inactive. Although commercial platinum exhibits excellent ORR catalytic activity, its poor methanol resistance and long-time durability severely restrict its sustainable development and application. This work synthesized Ti 4 O 7 /CNT nanocomposite electrocatalysts by using the sol-gel method followed by high-temperature carbothermal reduction. The obtained catalysts exhibit a large electrochemically active surface area (347.89 cm 2 ) and low interfacial charge transfer resistance (64.5 Ω). The reduction potential (0.73 V), onset potential (0.93 V), half-wave potential (0.73 V), and electron transfer number (3.7) of this electrocatalyst are all close to those of the Pt/C electrocatalysts in alkaline medium. Simultaneously, it also possesses remarkable methanol tolerance and long-term durability, whose relative current density can maintain above 74% after cycling for 24 h.