采用改进的多元醇法制备了PtNi(原子比1∶1)质量分数为60%的高金属载量碳载PtNi合金(PtNi/C),通过在450℃下退火处理获得了碳载PtNi金属间化合物氧还原电催化剂.该催化剂对氧还原的质量比活性和面积比活性分别是商业化Pt/C(JMPt/C)催化剂的1.66和2.3倍;并且加速耐久性测试后PtNi金属间化合物催化剂的质量比活性仍与Pt/C的初始性能相当,耐久性得到了大幅提升.PtNi/C金属间化合物催化剂氧还原活性和稳定性的提高归因于PtNi的有序原子排布结构及催化剂表面零价金属含量的提高.
PtNi / C disordered alloy nanoparticles,synthesized in ethylene glycol solution,were annealed and converted into ordered PtNi / C intermetallic nanoparticles. Such an ordered intermetallic PtNi / C catalyst showed enhanced specific activity and mass activity,which were about 2.3 and 1.66 times those of Pt / C for the oxygen reduction reaction( ORR),in comparison with the Pt / C catalyst. After accelerated stress tests( ASTs),the ORR mass activity of the Pt/C and PtNi/C intermetallic nanoparticles decreased to 88.92% and36.95% of the initial values,respectively; and the mass activity of PtNi / C intermetallic nanoparticles after ASTs was equivalent to the initial one of the Pt / C catalyst. The enhanced ORR activity and durability of the PtNi / C intermetallic nanoparticles could be attributed to the ordered atomic configuration and the increased content of zero valence metal on the surface of nanoparticles. Moreover,the ordered PtNi / C intermetallic nanoparticles exhibited higher methanol tolerance during the ORR than the Pt / C catalyst.