碳纳米管负载碳化钨及其性能研究
关键词：碳纳米管；偏钨酸铵；碳化钨；钯；直接乙醇燃料电池；程序升温法
Abstract
Tungsten carbides (WC) nanoparticles were synthesized on carbon nanotube (CNT) by a temperature programmed reaction (TPR) method. The influence of the CNT and the difference of WC’s percentage composition toward the performance of the catalyst are discovered. The particle size of WC can be controlled between 8nm to 9nm. The particle size of WC can be achieved to among 16nm. The comparison among samples is based on the X-ray diffraction (XRD), electrochemical testing and scanning electron microscope (SEM) analysis. The XRD results demonstrated the mechanism of the WC’s transformation. The testing results demonstrated that the peak current of Pd/30%WCMH3 is 5.007×10-3A, and the peak potential is -0.1173V. When comparing the electrolyte with different concentration of KOH, we find out that the best electrochemical performance occurs at the concentration of 2M. The peak current is 8.49×10-3A and the peak potential is -0.153V. The linear fitting of log(j)~log(CEtOH) shows that the order of reaction of KOH is about 0.7. The anodic transfer coefficient is 0.11. The diffusion coefficient is calculated as 4.108×10-5cm2s-1 when the concentration of KOH and EtOH is both 1M.
Key Words: carbon nanotube; ammonium metatungstate; tungsten carbides; palladium; direct ethanol fuel cell; temperature programmed reaction
目 录
1. 绪论 1
1.1. 直接乙醇燃料电池背景简介 1
1.2. 催化剂 1
1.2.1. WC催化剂 1
1.2.2. WC催化剂制备方法 2
1.3. 催化剂载体 4
1.3.1. 碳纳米管（CNT） 4
1.4. 研究课题内容及方案 4
1.4.1. 研究课题内容 4
1.4.2. 研究课题方案 5
2. 实验部分 6
2.1. 实验药品与仪器 6
2.1.1. 试剂与气体 6
2.1.2. 仪器 6
2.2. 实验步骤 6
2.2.1. 制备WCMH1 6
2.2.2. 催化剂负载钯（Pd） 8
2.3. 表征 8
2.3.1. X射线衍射测试（XRD） 8
2.3.2. 元素分析(EDS) 8
2.3.3. 比表面积与孔径分布表征 8
2.3.4. 电化学测试 9
3. 实验结果与分析 10
3.1. MH1、MH3、MH7、MH8的吸脱附等温曲线图 10
3.2. 孔径分布柱状图 11
3.3. XRD物相分析 12
3.4. EDS测试与分析 22
3.5. 电化学测试 23
3.5.1. 不同WC含量的WCMH1在负载Pd之后的循环伏安测试 23
3.5.2. WCMHx在负载Pd之后的循环伏安测试 24
3.5.3. 30%WC含量下不同载体负载Pd之后循环伏安测试对比 25