Pd-Co/CNT复合催化剂的制备及甲醇电氧化性能

以Pd Cl₂和Co(NO₃)₂为原料，采用分步乙二醇还原法制备了多壁碳纳米管负载Pd-Co复合纳米催化剂Pd-Co/CNT。利用TEM、XRD和XPS对催化剂的结构进行了表征，考察了其甲醇电氧化性能。结果显示，Co的引入使Pd催化剂的分散性得到改善，其电化学表面积可达39.7 m²/g。循环伏安测试表明，当Pd∶Co物质的量比为1∶0.2时，Pd-Co/CNT的甲醇氧化峰电流密度约为Pd/CNT的2.7倍。计时电流结果表明，Co的添加使催化剂的活性衰减比例由Pd/CNT的63.8%降至54.2%，显示出较强的抗中毒能力。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。

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

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.