Wang Zilong, Xiao Shuang, Zhu Zonglong, Long Xia, Zheng Xiaoli, Lu Xihong, Yang Shihe
Department of Chemistry, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong, China.
ACS Appl Mater Interfaces. 2015 Feb 25;7(7):4048-55. doi: 10.1021/am507744y. Epub 2015 Feb 17.
Electrocatalysts for the oxygen reduction and evolution reactions (ORR/OER) are often functionally separated, meaning that they are only proficient at one of the tasks. Here we report a high-performance bifunctional catalyst for both ORR and OER in both alkaline and neutral media, which is made of cobalt-embedded nitrogen doped carbon nanotubes. In OER, it shows an overpotential of 200 mV in 0.1 M KOH and 300 mV in neutral media, while the current density reaches 50 mA cm(-2) in alkaline media and 10 mA cm(-2) in neutral media at overpotential of 300 mV. In ORR, it is on par with Pt/C in both alkaline and neutral media in terms of overpotential, but its stability is superior. Further study demonstrated that the high performance can be attributed to the coordination of N to Co and the concomitant structural defects arising from the transformation of cobalt-phthalocyanine precursor.
用于氧还原和析氧反应（ORR/OER）的电催化剂通常在功能上是分开的，这意味着它们仅擅长其中一项任务。在此，我们报道了一种在碱性和中性介质中均适用于ORR和OER的高性能双功能催化剂，它由嵌入钴的氮掺杂碳纳米管制成。在OER中，它在0.1 M KOH中显示出200 mV的过电位，在中性介质中为300 mV，而在300 mV过电位下，电流密度在碱性介质中达到50 mA cm(-2)，在中性介质中达到10 mA cm(-2)。在ORR中，它在碱性和中性介质中的过电位方面与Pt/C相当，但其稳定性更优。进一步研究表明，高性能可归因于N与Co的配位以及钴酞菁前体转变产生的伴随结构缺陷。
