PdCu合金纳米晶体的制备和电催化活性研究

改变表面活性剂1-十八烯（ODE）和油胺（OLA）或油酸（OA）的配比，以1,2-二羟基十六烷二醇作还原剂同时还原乙酰丙酮铜Cu(acac)2和乙酰丙酮钯Pd(acac)2一步法制备了单分散的球形和米花形的PdCu纳米粒子.透射电子显微镜和XRD等结构表征表明，两种形状的PdCu纳米粒子均为（111）面占优的合金纳米晶体，其平均粒径分别为12.7 ± 0.18 和 20.4 ± 0.31 nm.电化学循环伏安法（CV）测定了两种PdCu合金纳米粒子对甲酸氧化的电催化活性.结果表明，在球形PdCu纳米粒子上得到的甲酸氧化峰电流密度约为米花状纳米粒子（PdCu-B）上的5.6倍.同时，前者显示出了更好的抗CO毒化能力.计时电流测量也表明，球状PdCu纳米粒子比米花状纳米粒子有更好的电催化稳定性能.

Synthesis and Electrocatalysis of PdCu Alloy Nanocrystals

Monodispersed PdCu alloy nanoparticles were synthesized by co-reduction of Cu(acac)2 and Pd(acac)2 with 1, 2-hexadecanediol. The spherical and popcorn-like shapes of PdCu alloy nanoparticles were obtained by changing the ratios of mixed surface protecting ligands of 1-octadecene, and oleylamine or oleic acid. TEM and XRD measurements showed that both PdCu nanoparticles are alloy nanocrystals dominated with (111) planes and the average sizes are 12.7 ± 0.18 and 20.4 ± 0.31 nm for he spherical and popcorn-like PdCu nanoparticles, respectively. The electrocatalytic activities of the PdCu nanocrystals for formic acid oxidation were evaluated by electrochemical cyclic voltammetry (CV). The result showed that the peak current density of formic acid oxidation on the spherical PdCu nanocrystals is 6.5 times higher than that on the popcorn-like PdCu nanoparticles. Moreover, by comparing the ratio of the current density of the first anodic peak to the cathodic peak, the spherical PdCu nanocrystals exhibit better tolerance to CO poisoning than that of the popcorn-like counterparts. Chronoamperometric measurement indicated that the spherical PdCu nanocrystals have better activity and stability for formic acid oxidation compared to the popcorn-like PdCu nanoparticles.