Wu Xingqiao, Xu Qingfeng, Yan Yucong, Huang Jingbo, Li Xiao, Jiang Yi, Zhang Hui, Yang Deren
State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University Hangzhou 310027 P. R. China
RSC Adv. 2018 Oct 11;8(61):34853-34859. doi: 10.1039/c8ra07415a. eCollection 2018 Oct 10.
Pd@Pt core-shell nanocrystals with ultrathin Pt layers have received great attention as active and low Pt loading catalysts for oxygen reduction reaction (ORR). However, the reduction of Pd loading without compromising the catalytic performance is also highly desired since Pd is an expensive and scarce noble-metal. Here we report the epitaxial growth of ultrathin Pt shells on Pd Cu truncated octahedra by a seed-mediated approach. The Pd/Cu atomic ratio () of the truncated octahedral seeds was tuned from 2, 1 to 0.5 by varying the feeding molar ratio of Pd to Cu precursors. When used as catalysts for ORR, these three Pd Cu@Pt core-shell truncated octahedra exhibited substantially enhanced catalytic activities compared to commercial Pt/C. Specifically, PdCu@Pt catalysts achieved the highest area-specific activity (0.46 mA cm) and mass activity (0.59 mA μg ) at 0.9 V, which were 2.7 and 4.5 times higher than those of the commercial Pt/C. In addition, these Pd Cu@Pt core-shell catalysts showed a similar durability with the commercial Pt/C after 10 000 cycles due to the dissolution of active Cu and Pd in the cores.
具有超薄铂层的钯@铂核壳纳米晶体作为氧还原反应（ORR）的活性和低铂负载催化剂受到了广泛关注。然而，由于钯是一种昂贵且稀缺的贵金属，在不影响催化性能的情况下降低钯负载量也非常必要。在此，我们报道了通过种子介导法在钯 铜截角八面体上外延生长超薄铂壳。通过改变钯与铜前驱体的进料摩尔比，将截角八面体种子的钯/铜原子比（）从2、1调整到0.5。当用作ORR催化剂时，与商业铂/碳相比，这三种钯 铜@铂核壳截角八面体表现出显著增强的催化活性。具体而言，钯铜@铂催化剂在0.9 V时实现了最高的面积比活性（0.46 mA cm）和质量活性（0.59 mA μg），分别比商业铂/碳高2.7倍和4.5倍。此外，由于活性铜和钯在核中的溶解，这些钯 铜@铂核壳催化剂在10000次循环后与商业铂/碳表现出相似的耐久性。
