Pd-Co/CNT复合催化剂的制备及甲醇电氧化性能

Preparation and methanol electrooxidation performance of composite Pd-Co/CNT catalyst

摘要:

纳米Pd催化剂是碱性直接甲醇燃料电池性能优良的阳极催化剂。向Pd催化剂中添加过渡金属组分,可以通过协同效应改善催化剂的性能。以分步乙二醇还原法制备了碳纳米管负载非合金Pd-Co复合纳米催化剂,并考察其甲醇电氧化性能。结果显示,Co的引入可以改善Pd纳米粒子的分散性,增大催化剂的电化学表面积,并显著提高催化剂的动力学性能。循环伏安测试表明,Pd-Co/CNT(1:0.2)催化剂的甲醇氧化峰电流密度约为Pd/CNT催化剂的2.7倍。计时电流试验结果表明,Pd-Co/CNT(1:0.2)催化剂的活性衰减速率低于Pd/CNT催化剂,具有较强的抗中毒能力。Pd-Co复合催化剂性能的改善归因于Pd与Co之间的协同相互作用。

Abstract:

Pd nanocatalyst is an excellent anode catalyst for alkaline direct methanol fuel cell. The performance of the Pd catalyst can be improved through synergistic effect by adding a transition metal. Carbon nanotube supported non-alloyed Pd-Co bimetallic nano-catalysts were prepared by a step-by-step ethylene glycol reduction method, and their performances for methanol electrooxidation were investigated. The results show that the introduction of Co can improve the dispersion of Pd nanoparticles so as to increase the electrochemical surface area of the catalyst, and significantly improve the kinetic property of the catalyst. The cyclic voltammetry test showed that the peak current density of methanol oxidation over Pd-Co/CNT(1:0.2) catalyst was about 2.7 times that of Pd/CNT catalyst. The chronoamperometry test indicated that Pd-Co/CNT(1:0.2) catalyst had a lower activity decay rate than Pd-Co/CNT catalyst, showing a strong anti-poisoning ability. The improvement in the performance of Pd-Co/CNT catalyst is attributed to the synergistic interaction between Pd and Co. Yet, the current protocol can be used to grow and assemble other multi-metallic catalysts.