Mahmood Azhar, Xie Nanhong, Ud Din Muhammad Aizaz, Saleem Faisal, Lin Haifeng, Wang Xun
Key Lab of Organic Optoelectronics and Molecular Engineering , Department of Chemistry , Tsinghua University , Beijing , 100084 , China . Email:
Chem Sci. 2017 Jun 1;8(6):4292-4298. doi: 10.1039/c7sc00318h. Epub 2017 Mar 22.
Mechanistic control is a powerful means for manufacturing specific shapes of metal nanostructures and optimizing their performance in a variety of applications. Thus, we successfully synthesized multimetallic nanoplates (PtAgBiCo and PtAgBi) by combining the concepts of crystal symmetry, oxidative etching and seed ratio, and tuned their activity, stability and methanol tolerance, as well as Pt utilization, for the oxygen reduction reaction in direct methanol fuel cells. Systematic studies reveal that the formation of PtAgBiCo triangular nanoplates with a high morphological yield (>90%) can be achieved by crystallinity alteration, while electrochemical measurements indicate that the PtAgBiCo nanoplates have superior electrocatalytic activity towards the oxygen reduction reaction. The specific and mass activity of the PtAgBiCo nanoplates are 8 and 5 times greater than that of the commercial Pt/C catalyst, respectively. In addition, the tetrametallic PtAgBiCo nanoplates exhibit a more positive half-wave potential for the oxygen reduction reaction and possess an excellent methanol tolerance limit compared with the commercial Pt/C catalyst.
机理控制是制造特定形状金属纳米结构并在各种应用中优化其性能的有力手段。因此，我们通过结合晶体对称性、氧化蚀刻和种子比例的概念，成功合成了多金属纳米板（PtAgBiCo和PtAgBi），并针对直接甲醇燃料电池中的氧还原反应，调节了它们的活性、稳定性和甲醇耐受性以及铂利用率。系统研究表明，通过结晶度改变可实现具有高形态产率（>90%）的PtAgBiCo三角形纳米板的形成，而电化学测量表明，PtAgBiCo纳米板对氧还原反应具有优异的电催化活性。PtAgBiCo纳米板的比活性和质量活性分别比商业Pt/C催化剂高8倍和5倍。此外，与商业Pt/C催化剂相比，四金属PtAgBiCo纳米板在氧还原反应中表现出更正的半波电位，并且具有出色的甲醇耐受极限。
