当前位置: X-MOL 学术J. Am. Chem. Soc. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Improvement of Oxygen Reduction Performance in Alkaline Media by Tuning Phase Structure of Pd–Bi Nanocatalysts
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2021-09-14 , DOI: 10.1021/jacs.1c08644
Ming Zhou 1 , Jiangna Guo 2 , Bo Zhao 3 , Can Li 1 , Lihua Zhang 4 , Jiye Fang 1
Affiliation  

Tuning the crystal phase of bimetallic nanocrystals offers an alternative avenue to improving their electrocatalytic performance. Herein, we present a facile and one-pot synthesis approach that is used to enhance the catalytic activity and stability toward oxygen reduction reaction (ORR) in alkaline media via control of the crystal structure of Pd–Bi nanocrystals. By merely altering the types of Pd precursors under the same conditions, the monoclinic structured Pd5Bi2 and conventional face-centered cubic (fcc) structured Pd3Bi nanocrystals with comparable size and morphology can be precisely synthesized, respectively. Interestingly, the carbon-supported monoclinic Pd5Bi2 nanocrystals exhibit superior ORR activity in alkaline media, delivering a mass activity (MA) as high as 2.05 A/mgPd. After 10,000 cycles of ORR durability test, the monoclinic structured Pd5Bi2/C nanocatalysts still remain a MA of 1.52 A/mgPd, which is 3.6 times, 16.9 times, and 21.7 times as high as those of the fcc Pd3Bi/C counterpart, commercial Pd/C, and Pt/C electrocatalysts, respectively. Moreover, structural characterizations of the monoclinic Pd5Bi2/C nanocrystals after the durability test demonstrate the excellent retention of the original size, morphology, composition, and crystal phase, greatly alleviating the leaching of the Bi component. This work provides new insight for the synthesis of multimetallic catalysts with a metastable phase and demonstrates phase-dependent catalytic performance.

中文翻译:

通过调节 Pd-Bi 纳米催化剂的相结构提高碱性介质中的氧还原性能

调整双金属纳米晶体的晶相为提高其电催化性能提供了另一种途径。在此,我们提出了一种简便的一锅法合成方法,通过控制 Pd-Bi 纳米晶体的晶体结构来提高碱性介质中氧还原反应 (ORR) 的催化活性和稳定性。通过在相同条件下仅改变Pd前驱体的类型,可以分别精确地合成具有相当尺寸和形态的单斜结构Pd 5 Bi 2和常规面心立方( fcc )结构的Pd 3 Bi纳米晶体。有趣的是,碳负载的单斜Pd 5Bi 2纳米晶体在碱性介质中表现出优异的 ORR 活性,提供高达 2.05 A/mg Pd的质量活性 (MA) 。经过 10,000 次循环的 ORR 耐久性测试,单斜结构 Pd 5 Bi 2 /C 纳米催化剂的 MA 仍然保持在 1.52 A/mg Pd,是fcc Pd 3 Bi 的3.6 倍、16.9 倍和 21.7 倍/C 对应物,分别是商业 Pd/C 和 Pt/C 电催化剂。此外,单斜Pd 5 Bi 2 的结构特征耐久性测试后的 /C 纳米晶体显示出对原始尺寸、形态、组成和晶相的出色保留,大大减轻了 Bi 组分的浸出。这项工作为合成具有亚稳相的多金属催化剂提供了新的见解,并展示了相依赖的催化性能。
更新日期:2021-09-29
down
wechat
bug