预制铂纳米颗粒对质子交换膜燃料电池用铂纳米线阴极的结构影响

Effects of Preformed Pt Nanoparticles on Structure of Platinum Nanowire Cathode for Proton Exchange Membrane Fuel Cells

铂纳米线(Pt NWs)由于其独特的结构特点,比商业Pt/C具有更高的氧还原反应(ORR)比活性。在本工作中,我们将预先制备好的铂纳米颗粒(Pt NPs)引入到碳基体中,用于诱导生长Pt NWs,获得了均匀分布Pt NWs的阴极。通过改变Pt NP载量(0~0.015 mg·cm^(-2))和Pt NP来源(不同Pt含量的Pt/C)研究了所制备阴极的结构和性能。用扫描电镜对阴极表面进行了表征,并用透射电镜和X射线衍射分析了Pt NW的形貌和晶体结构。在单电池中分别进行了极化曲线和循环伏安曲线测试。当Pt NP来源为40%Pt/C且其载量为0.005 mg·cm^(-2)时,制备的Pt NW阴极具有最佳的单电池性能和最大的电化学表面积(ECSA)。最后,提出了预制Pt NP影响Pt NWs分布的可能机制。

Pt nanowires(Pt NWs) have been demonstrated to have a higher specific activity of oxygen reduction reaction(ORR) than that of commercial Pt/C due to their unique structural characteristics. In this work, a cathode with a uniform distribution of Pt NWs was obtained by introducing preformed Pt nanoparticles(NPs) into the carbon matrix to induce Pt NW growth. The structure and performance of the as-prepared cathode were investigated by altering Pt NP loadings(0-0.015 mg·cm^(-2)) and Pt NP sources(Pt/C with different Pt contents). The cathode surface was characterized by scanning electron microscopy(SEM), and the morphology and crystal structure of Pt NW were analyzed by transmission electron microscopy(TEM) and X-ray diffraction(XRD). Polarization and cyclic voltammetry curves were obtained in single cells. The best single-cell performance, as well as the largest electrochemical surface area(ECSA) value was achieved by the cathode with preformed Pt NP loading of 0.005 mg·cm^(-2)originating from 40% Pt/C. Finally, a possible mechanism for the influence of preformed Pt NPs in the Pt NW distribution was proposed.