当前位置: X-MOL 学术New Carbon Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Co, N co-doped porous carbons as high-performance oxygen reduction electrocatalysts
New Carbon Materials ( IF 6.5 ) Pub Date : 2021-03-15 , DOI: 10.1016/s1872-5805(21)60016-1
Jing Zhang , Lianghao Song , Chenfei Zhao , Xiuping Yin , Yufeng Zhao

Although the Co and N co-doped carbon catalyst (Co-NC) has attracted much attention because of its low cost and the natural abundance of the dopants, it has a low oxygen reduction reaction (ORR) activity and a high selectivity for the two-electron (2e-) reduction of oxygen to H2O2, which affects its use in fuel cells. Co-NC catalysts were prepared by the pyrolysis of a mixture of cobalt chloride and chitosan pretreated with zinc chloride at 650, 750 and 850 oC, followed by washing with nitric acid and annealing at 900 oC. The results indicate that zinc chloride helps the complexing of chitosan with Co2+, which is also a chemical activator that generates pores, and annealing caused the evaporation of the spherical Zn metal nanoparticles formed by the carbothermal reduction of Zn ions, leading to a unique porous structure of the catalysts with spherical pores filled with spherical carbon nanoparticles formed by the growth of nitrogen-doped carbon as a result of the Co catalyst. The degree of graphitization is also improved by the Co catalyst. The Co-NC catalyst obtained at a pyrolysis temperature of 750 oCshows the same four-electron (4e-) reduction of oxygen as a commercial Pt/C catalyst, and a significantly higher ORR catalytic activity, longer-term stability and better methanol tolerance than a commercial Pt/C catalyst. These are due to its large specific surface area, high contents of pyridinic nitrogen and graphitic nitrogen that disperse the Co species and its excellent electrical conductivity.



中文翻译:

Co,N共掺杂多孔碳作为高性能氧还原电催化剂

尽管Co和N共掺杂碳催化剂(Co-NC)由于其成本低和掺杂剂的自然丰度而备受关注,但它具有较低的氧还原反应(ORR)活性和对这两种催化剂的高选择性π电子(2E - )氧还原成H 2 ö 2,这会影响燃料电池中的使用。助NC催化剂通过的混合物的热解制备的氯化钴和壳聚糖预处理氯化锌在650,750和850 ö C,接着用在900硝酸和退火洗涤ö C.结果表明,氯化锌有助于壳聚糖与Co 2+的络合,它也是产生孔的化学活化剂,退火导致通过碳热还原Zn离子形成的球形Zn金属纳米颗粒的蒸发,从而导致催化剂的独特多孔结构,其中球形孔填充了由碳形成的球形碳纳米颗粒。 Co催化剂的作用是氮掺杂碳的生长。钴催化剂还改善了石墨化程度。在750热解温度得到的共NC催化剂ö Cshows同一四电子(4E -)作为商用Pt / C催化剂还原氧气,并且比商用Pt / C催化剂具有更高的ORR催化活性,长期稳定性和更好的甲醇耐受性。这归因于其大的比表面积,分散Co物种的高含量的吡啶氮和石墨氮以及出色的导电性。

更新日期:2021-03-15
down
wechat
bug