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

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。

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

Polymerization reaction of pyrrole in the presence of Fe³⁺ and Co²⁺ 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. The oxygen reduction reaction (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.