Co掺杂ZIF-8衍生合成高效Co-N-C氧还原催化剂的研究

Cobalt-Doped ZIF-8-Derived High-Performance Co-N-C Oxygen Reduction Catalyst

在合成中添加Co(NO_(3))_(2)·6H_(2)O制备钴掺杂的2-甲基咪唑锌盐材料,通过优化钴掺杂量及热解温度得到了具有高比表面积(888 m^(2)/g)且同时存在微孔和介孔(孔体积为0.591 cm^(3)/g)的高效Co-N-C催化剂。电化学测试表明:Co-N-C催化剂具有良好的酸性氧还原催化活性、稳定性和抗甲醇毒化性能,其在0.1 mol/L HClO_(4)溶液中的氧还原途径主要是4电子反应过程,半波电位达到0.807 V,稳定性可与商业Pt/C催化剂相媲美。物理表征结果表明:钴元素成功地掺杂到Co-N-C催化剂中,较高的石墨化程度、良好的导电性、丰富的孔结构和Co-Nx活性位点,极大地提高了Co-N-C催化剂在酸性条件下的氧还原催化性能。本工作为合成ZIFs衍生的高效氧还原催化剂提供了新的思路。

Cobalt-doped 2-methylimidazole zinc salt material was prepared by adding(NO_(3))_(2)·6H_(2)O in the synthesis.The Co-N-C catalyst with high specific surface area(888 m^(2)/g)and coexistence of micropore and mesoporous structure(pore volume 0.591 cm^(3)/g)was synthesized by optimizing the amount of cobalt doped and the pyrolysis temperature.Electrochemical tests show that Co-N-C catalyst has good catalytic activity and stability for oxygen reduction and good resistance to methanol poisoning in acidic media.The oxygen reduction catalytic process of Co-N-C catalyst in 0.1 mol/L perchloric acid solution is mainly via a 4-electron pathway,and the half-wave potential reaches 0.807 V.It is found that the stability of the catalyst is almost the same as that of commercial Pt/C catalyst.The physical characterization results show that the metal cobal element is successfully doped into the Co-N-C system,generating high degree of graphitization,good conductivity,and rich porous structure and Co-Nxactive sites,which greatly improves the catalytic performance of Co-N-C under acidic conditions.This work provides a new idea for the synthesis of ZIFsderived high-performance oxygen reduction catalysts.