摘要
采用超声辅助化学法和凝胶化反应相结合的工艺制备了中空铂镍/三维石墨烯电催化剂(PtNi/GCM).利用X射线粉末衍射仪(XRD)、X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等表征了催化剂的结构、组成及微观形貌.采用电化学工作站和旋转圆盘电极测试了催化剂对氧还原反应的电催化活性和稳定性.结果表明,铂和镍前驱体的不同摩尔比对催化剂的多孔结构、粒子形貌和分散状态影响较大,当摩尔比为1∶1时,所得三维石墨烯中纳米粒子尺寸均一、分散均匀.该PtNi/GCM催化剂对氧还原具有优异的催化活性,在半波电势(0.494 V)处,质量比活性和面积比活性分别为1.09 A/mg Pt和1.02 m A/cm^2,是商业Pt/C的5.4倍和3.5倍(0.20 A/mgPt,0.29 m A/cm2).同时,该催化剂还具有很好的稳定性,循环30000周后,半波电势降低值是商业铂炭的43.6%.
Hollow platinum nickel/graphene cellular monolith（ Pt Ni/GCM） electrocatalysts were synthesized via a two-step method of sonochemical-assisted reduction and gelatinization reaction. X-ray diffraction（ XRD）,X-ray photoelectron spectroscopy（ XPS）,scanning electronic microscopy（ SEM） and transmission electron microscopy（ TEM） were employed to characterize the structures,compositions and morphologies of as-prepared catalysts. The activity and stability of the catalysts for oxygen reduction reaction（ ORR） were studied with electrochemical workstation and rotating disk electrode（ RDE）. The results show that different molar ratios of Pt to Ni in the precursor have great influence on the porous structure,particle morphology and dispersion of the catalyst. In particular,the Pt Ni/GCM electrocatalyst that was prepared with Pt/Ni molar ratio of 1 ∶ 1 in the precursor has the desirable structure and was uniformly distributed. The Pt Ni/GCM showed the excellent electrocatalytic activities and durability toward ORR. The mass and specific activities at half-wave potential of0. 494 V were 1. 09 A/mgPtand 1. 02 m A/cm2,respectively,which were 5. 4 and 3. 5 times those of commercial Pt/C（ 0. 20 A/mgPtand 0. 29 m A/cm2）.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2016年第8期1476-1484,共9页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:51572114)
江苏大学青年人才基金(批准号:15JDG078)资助~~
关键词
三维石墨烯
铂镍纳米粒子
中空结构
氧还原反应
电催化剂
Graphene cellular monolith
PtNi nanoparticles
Hollow structure
Oxygen reduction reaction
Electrocatalyst
