金属掺杂聚吡咯碳化物PPY-M的制备及其氧还原反应电催化活性

Carbonizing Products of the Fe/Co Doped Polypyrrole as Efficient Electrocatalysts for Oxygen Reduction Reaction

在Fe3+或Co2+存在下进行吡咯的聚合反应,得到金属离子掺杂的聚吡咯,并在N2气氛下700℃碳化,再将该碳化产物在900℃焙烧得到含有不同金属的复合催化剂PPY-M(M为不同的金属)。采用SEM、XRD等对催化剂的结构进行了表征。通过循环伏安和线性电位扫描等电化学手段,研究了催化剂对氧还原(ORR)的电催化活性及其稳定性。结果表明,掺杂金属钴的催化剂的活性最好,在酸性溶液中ORR的起始电位达到0.54 V(vs SCE),电流密度为7.5 mA/mg@-0.3 V(vs SCE);在碱性溶液中ORR的起始电位为-0.11 V(vs SCE),电流密度为5.7 mA/mg@-0.8 V。Fe或Co掺杂的聚吡咯碳化物对ORR具有较强的电催化活性,而且制备过程简单、成本低,有较重要的研究意义。

Polymerization reaction of pyrrole in the presence of Fe^3＋ and Co^2＋ was carried out to synthesize the metal -doped polypyrrole （PPy）. The metal-doped PPy was then calcined at 700℃ to obtain the carbonized products. Finally, the carbonized products were heated to 900℃ to synthesize the catalysts PPY-M（M is Fe or Co）. The structure of the catalysts was investigated by SEM and X-ray diffraction techniques. ORR activities of the catalysts in acidic and alkaline media were tested by voltammetry. Results show that the catalyst PPY-Co presents the highest electrocatalytic activity for ORR. The ORR current density at rotation rate of 2000 r/min is 7.5 mA/mg@0.3 V（vs SCE） in acidic solution and 5.7 mA/mg@0.8 V（vs SCE） in alkaline solution, and the onset potential of ORR is 0.54 V（vs SCE） in acidic solution and 0.11V（vs SCE） in alkaline solution. It is of great significance for the study of carbonizing products of PPY as efficient catalysts for ORR because of their simple preparation and low cost. v