碳纳米管负载四硝基金属酞菁-MnO2双催化剂催化氧还原性能

过渡金属酞菁具有很高的氧还原催化活性, MnO₂对氧还原反应有催化作用,但是将过渡金属酞菁和MnO₂作为氧还原反应的双催化剂的研究较少。 本文采用苯酐-尿素法合成了碳纳米管(CNT)负载四硝基金属酞菁(TNMPc)组装体,联合γ-MnO₂作为氧还原反应的双催化剂。 借助循环伏安法对双催化剂的配比进行优化,得到二者的最佳比例。 研究了四硝基金属酞菁的中心金属离子对最佳比例双催化剂催化性能的影响和双催化剂的抗甲醇性能,结果表明,双催化剂对氧还原反应的催化能力主要受到金属离子本性的影响,双催化剂对氧还原反应的催化效率顺序为CNT/TNFePc-MnO₂>CNT/TNCoPc-MnO₂>CNT/TNNiPc-MnO₂>CNT/TNCuPc-MnO₂;4种双催化剂均具有较好的抗甲醇中毒性能。

Catalytic Oxygen Reduction Property of Carbon Nanotubes Supported Tetra-nitro-metal Phthalocyanines-MnO2 Dual Catalysts

The transition metal phthalocyanine has a high catalytic activity for oxygen reduction. MnO₂ can catalyze the oxygen reduction reaction. However, the use of transition metal phthalocyanine and MnO₂ as dual catalysts for oxygen reduction is quite few. Four types of carbon nanotubes supported tetra-nitro-metal phthalocyanines assemblies(CNT/TNMPc) were synthesized by phthalic anhydride-urea method. Dual catalyst CNT/TNMPc-MnO₂ was prepared via adding γ-MnO₂ into CNT/TNMPc. The optimal ratio of CNT/TNMPc to MnO₂ was obtained by means of cyclic voltammetry. Effects of central metal ions of CNT/TNMPc on the catalytic performance for oxygen reduction reactivity were investigated. The results show that the catalytic efficiency order of the dual catalyst for oxygen reduction reactivity is CNT/TNFePc-MnO₂>CNT/TNCoPc-MnO₂>CNT/TNNiPc-MnO₂>CNT/TNCuPc-MnO₂. All of those suggest that the catalytic activity of dual catalysts for oxygen reduction reaction is mainly affected by the nature of metal ions. In addition, the anti methanol performance of dual catalyst was tested in 0.1 mol/L KOH+0.5 mol/L CH₃OH electrolyte solution. The results indicate that methanol-tolerant abilities of the CNT/TNMPc-MnO₂ are excellent.