Investigation of Pt/WC/C catalyst for methanol electro-oxidation and oxygen electro-reduction
Investigation of Pt/WC/C catalyst for methanol electro-oxidation and oxygen electro-reduction
复制标题
DOI：
10.1016/j.jpowsour.2008.07.067
复制
发表时间：
2008-12
影响因子：
9.2
通讯作者：
M. Jeon;K. Lee;W. Lee;H. Daimon;A. Nakahara;S. Woo
中科院分区：
文献类型：
--
作者：
M. Jeon;K. Lee;W. Lee;H. Daimon;A. Nakahara;S. Woo
开发了 Pt/WC/C 催化剂，以提高 Pt/C 催化剂的甲醇电氧化 (MOR) 和氧电还原 (ORR) 活性。循环伏安法和CO溶出结果表明，Pt/WC/C中发生了H+的溢出，这通过比较H+和CO的解吸面积值证实了这一点。在CO溶出测试结果中观察到CO电氧化峰的电位从Pt/C的0.81V显着降低到Pt/WC/C的0.68V。这表明通过用WC替代碳载体实现了CO电氧化活性的增加。通过 CO 剥离、透射电子显微镜和能量色散光谱浓度图的补充分析，研究了 Pt 在 WC 上而不是在碳载体上的优先沉积。 Pt/WC/C 催化剂对 MOR 的比活性为 170mAm−2。这比 Pt/C 催化剂（即 120mAm−2）高 42%。 Pt/WC/C 催化剂还表现出更高的 ORR 电流密度，即 0.87mAcm−2，而 0.7V 下 Pt/C 的电流密度为 0.36mAcm−2。在甲醇存在下，Pt/WC/C催化剂仍保持比Pt/C催化剂更高的电流密度。
A Pt/WC/C catalyst is developed to increase the methanol electro-oxidation (MOR) and oxygen electro-reduction (ORR) activities of the Pt/C catalyst. Cyclic voltammetry and CO stripping results show that spill-over of H+occurs in Pt/WC/C, and this is confirmed by comparing the desorption area values for H+and CO. A significant reduction in the potential of the CO electro-oxidation peak from 0.81V for Pt/C to 0.68V for Pt/WC/C is observed in CO stripping test results. This indicates that an increase in the activity for CO electro-oxidation is achieved by replacing the carbon support with WC. Preferential deposition of Pt on WC rather than on the carbon support is investigated by complementary analysis of CO stripping, transmission electron microscopy and concentration mapping by energy dispersive spectroscopy. The Pt/WC/C catalyst exhibits a specific activity of 170mAm−2for MOR. This is 42% higher than that for the Pt/C catalyst, viz., 120mAm−2. The Pt/WC/C catalyst also exhibits a much higher current density for ORR, i.e., 0.87mAcm−2compared with 0.36mAcm−2for Pt/C at 0.7V. In the presence of methanol, the Pt/WC/C catalyst still maintains a higher current density than the Pt/C catalyst.