Bian Ting, Sun Biao, Luo Sai, Huang Long, Su Shan, Meng Chunfeng, Su Shichuan, Yuan Aihua, Zhang Hui
School of Energy and Power Engineering, Jiangsu University of Science and Technology Zhenjiang 212003 People's Republic of China.
School of Materials Science and Engineering, Jiangsu University of Science and Technology Zhenjiang 212003 People's Republic of China.
RSC Adv. 2019 Nov 4;9(61):35887-35894. doi: 10.1039/c9ra06893g. eCollection 2019 Oct 31.
Pt-based nanocrystals with a twinned structure are highly desirable to achieve high performances in both catalytic activity and durability for methanol oxidation reaction (MOR). However, it still remains great challenge for producing such twinned nanocrystals due to the high internal strain energy of Pt. Here we present a seed-mediated approach to generate Au@PtCu nanostars with a five-fold twinned structure using Au decahedra as seeds. The composition of Pt/Cu in the nanocrystals was tuned by varying the molar ratio of Pt to Cu salt precursors with the amount of Au seeds being the same. Through composition optimization, Au@PtCu nanostars achieved the highest specific (1.06 mA cm) and mass (0.18 mA mg ) activities for MOR, which were about 5.9 and 1.6 times higher than those of commercial Pt/C, respectively. After accelerated stability test (ADT) for 1500 cycles, such nanostars remained ∼95% of specific activity compared to a loss of ∼28% for commercial Pt/C, indicting their superior durability for MOR. We believed that this enhancement may arise from the unique twinned structure and possible synergetic effect between Pt and Cu components.
具有孪晶结构的铂基纳米晶体对于在甲醇氧化反应（MOR）的催化活性和耐久性方面实现高性能非常理想。然而，由于铂的高内部应变能，生产这种孪晶纳米晶体仍然面临巨大挑战。在此，我们提出一种种子介导的方法，以金十面体为种子生成具有五重孪晶结构的Au@PtCu纳米星。在金种子数量相同的情况下，通过改变铂与铜盐前驱体的摩尔比来调节纳米晶体中铂/铜的组成。通过组成优化，Au@PtCu纳米星实现了甲醇氧化反应的最高比活性（1.06 mA cm）和质量活性（0.18 mA mg），分别比商业铂碳催化剂高出约5.9倍和1.6倍。经过1500次循环的加速稳定性测试（ADT）后，这种纳米星的比活性仍保持约95%，而商业铂碳催化剂的比活性损失约28%，表明它们在甲醇氧化反应中具有优异的耐久性。我们认为这种增强可能源于独特的孪晶结构以及铂和铜组分之间可能的协同效应。
