State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
Department of Materials Science & Engineering, & Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, China.
Nanoscale. 2017 Jan 26;9(4):1738-1744. doi: 10.1039/c6nr08907k.
Herein, a novel material with an excellent electrocatalytic activity for the oxygen reduction reaction (ORR), composed of onion-like carbon@Co nanoparticles (NPs) incorporated on defect-rich N-doped graphene nanoribbons (C@Co-NGR), is prepared via a combination of nitric acid etching and subsequent high-temperature treatment of the as-synthesized C@Co-N doped carbon nanotubes. The as-prepared C@Co-NGR exhibits excellent electrocatalytic activity for the ORR in 0.10 M KOH with a half-wave potential of 0.830 V (vs. a reversible hydrogen electrode, RHE), which is 21 mV more positive than that of a commercial 20 wt% Pt/C catalyst. Moreover, it shows a higher stability and better methanol tolerance than the commercial Pt/C catalyst in alkaline solution, with almost no shift in the ORR polarization curve after 3000 cycles and no change of the ORR peak in the cyclic voltammogram in the presence of 1.0 M methanol. Most importantly, the C@Co-NGR also exhibits a comparable activity for the oxygen evolution reaction (OER) in 0.10 M KOH solution, in which the overpotential needed to achieve a current density of 10 mA cm is 410 mV, comparable to that of the state-of-the-art commercial RuO catalyst (370 mV, vs. RHE). This makes the C@Co-NGR one of the best non-precious-metal catalyst for OER and ORR in alkaline solution ever reported.
在此，通过对所合成的 C@Co-N 掺杂碳纳米管进行硝酸刻蚀和随后的高温处理，制备了一种具有优异氧还原反应（ORR）电催化活性的新型材料，由洋葱状碳@Co 纳米颗粒（NPs）嵌入在富缺陷的 N 掺杂石墨烯纳米带（C@Co-NGR）上组成。所制备的 C@Co-NGR 在 0.10 M KOH 中对 ORR 表现出优异的电催化活性，半波电位为 0.830 V（相对于可逆氢电极，RHE），比商业 20 wt%Pt/C 催化剂正 21 mV。此外，它在碱性溶液中表现出比商业 Pt/C 催化剂更高的稳定性和更好的甲醇耐受性，在 3000 次循环后 ORR 极化曲线几乎没有位移，在存在 1.0 M 甲醇的情况下循环伏安图中的 ORR 峰没有变化。最重要的是，C@Co-NGR 在 0.10 M KOH 溶液中对析氧反应（OER）也表现出相当的活性，其中达到 10 mA cm-2 电流密度所需的过电位为 410 mV，与最先进的商业 RuO2 催化剂（370 mV，相对于 RHE）相当。这使得 C@Co-NGR 成为碱性溶液中 OER 和 ORR 性能最好的非贵金属催化剂之一。
