Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1275926 | International Journal of Hydrogen Energy | 2013 | 6 Pages |
Solving slow kinetics of oxygen reduction reaction is critically important for the development of hydrogen fuel cells and direct methanol/ethanol fuel cells. In this study, graphene and nitrogen (N)-doped graphene were synthesized by a solvothermal method and investigated as catalysts as well as catalyst supports for oxygen reduction reactions. In comparison to graphene, N-doped graphene demonstrated higher electrocatalytic activity in both acidic and alkaline solutions. N-doped graphene can act directly as a catalyst to facilitate four-electron oxygen reductions in alkaline solution and two-electron reductions in acidic solution. On the other hand, when used as catalyst supports for Pt and Pt–Ru nanoparticles, N-doped graphene can contribute to four-electron oxygen reductions in acidic solution, yet demonstrate much slower reaction kinetics in alkaline solution. Our findings conclude that N-doped graphene can be developed as an efficient catalyst for oxygen reductions to replace the use of precious Pt catalysts in alkaline solution but not in acidic solution.
► Electrocatalytic activity of N-doped graphene in both acidic and alkaline solution. ► N-doped graphene can be directly used as a catalyst for ORR in alkaline solution. ► N-doped graphene is a two-electron oxidation catalyst for ORR in acidic solution. ► N-doped graphene activates Pt and Pt–Ru nanoparticles for ORR in acidic solution.