PtNi/C催化剂的合成及其对甲醇氧化的电催化性能

Synthesis of PtNi/C electrocatalysts and their electrocatalytic performance for methanol electrooxidation

用液体多元醇方法合成了PtNi/C纳米电催化剂,并对其进行了XRD和TEM表征.讨论了合成溶液的pH值对铂镍合金纳米粒子的粒径影响.结果表明,随着合成溶液pH值的增加,PtNi合金纳米粒子的粒径变小,并且更加均匀.当合成溶液的pH值为4.0、5.5、7.5和9.0时,铂镍合金纳米粒子的平均粒径分别是4.2、3.7、3.3和3.0 nm.用循环伏安和恒电位极化表征了PtNi/C纳米电催化剂在室温下对甲醇氧化的电催化性能.结果表明,当合成溶液的pH值为9.0时,合成的PtNi/C催化剂对甲醇的氧化具有较好的电催化性能,比Pt/C具有更稳定的电催化性能.

PtNi/C nanosized electrocatalysts were synthesized by a liquid polyol method, and the products were characterized by X-ray diffraction （XRD） and transmission electron microscopy（TEM）. The effects of the synthesis solution pH on the size and distribution of PtNi nanoparticles were discussed. PtNi nanoparticles become smaller and more uniform with the increase of synthesis solution pH. When the synthesis solution pH was 4.0, 5.5, 7.5 and 9.0, the mean size of PtNi nanoparticles was 4.2, 3.7, 3.3 and 3.0 nm, respectively. The electrocatalytic activity of the PtNi/C electrocatalyst for methanol electrooxidation was characterized by the cyclic voltrametry and chronoamperometry. The results indicated that when the synthesis solution pH is 9.0, the PtNi/C electrocatalyst exhibits better electrocatalytic performance and more stable electrocatalytic activity than Pt/C catalyst.