摘要
在无表面活性剂的情况下,制备Vulcan XC72担载的分散良好的空心PtCu纳米颗粒。TEM,HRTEM与HAADF-STEM确认了PtCu纳米颗粒的空心结构;HRTEM与XRD同时证实PtCu纳米颗粒发生晶格紧缩。通过XPS与CV,揭示由了由Pt表皮包覆PtCu合金的结构。在半电池测试中,PtCu/C表现出优于Pt/C(JM)的氧还原(ORR)电催化性能。良好的ORR催化活性得益于空心结构导致的晶格紧缩及亚表层合金效应所引起的含氧物种在PtCu表面吸附强度的减弱。此外,经过电化学加速衰竭测试后,空心PtCu纳米颗粒也表现出结构的稳定性:(1)空心结构并未消失,并且纳米颗粒尺寸并无显著变化;(2)PtCu/C的面积比活性与质量比活性并无明显改变。
Hollow PtCu nanoparticles supported on Vulcan XC72 were synthesized in the absence of surfactant. The hollow structure was evident in TEM, HRTEM and HAADF-STEM images. HRTEM indicated the lattice contraction of PtCu nanoparticles; XRD displayed the lattice compression of PtCu. Both XPS and CV demonstrated that PtCu nanoparticle was covered by Pt skin with subsurface PtCu alloy. Based on half-cell test, the PtCu/C electrocatalysts displayed impressive ORR performance compared with the Pt/C(JM). The enhanced ORR performance was attributed to the reduced adsorption strength of OHads on surface of PtCu, resulted from the hollow-induced lattice compression and subsurface alloy effect.
引文
[1]Nie,Y.;Li,L.and Wei,Z.Chemical Society Reviews.2015,44,2168.
[2]Cao,L.,Zhang,G.,Jiang,S.,Tang,X.,Qin,X.,Guo,X.,Shao,Z.and Yi,B.ChemE lectro Chem.2016,3,309.