Zhao Xuan, Wang Yu, Da Yunli, Wang Xinxia, Wang Tingting, Xu Mingquan, He Xiaoyun, Zhou Wu, Li Yafei, Coleman Jonathan N, Li Yanguang
Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, China.
College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China.
Natl Sci Rev. 2020 Aug;7(8):1360-1366. doi: 10.1093/nsr/nwaa084. Epub 2020 Apr 25.
The two-electron reduction of molecular oxygen represents an effective strategy to enable the green, mild and on-demand synthesis of hydrogen peroxide. Its practical viability, however, hinges on the development of advanced electrocatalysts, preferably composed of non-precious elements, to selectively expedite this reaction, particularly in acidic medium. Our study here introduces 2H-MoTe for the first time as the efficient non-precious-metal-based electrocatalyst for the electrochemical production of hydrogen peroxide in acids. We show that exfoliated 2H-MoTe nanoflakes have high activity (onset overpotential ∼140 mV and large mass activity of 27 A g at 0.4 V versus reversible hydrogen electrode), great selectivity (HO percentage up to 93%) and decent stability in 0.5 M HSO. Theoretical simulations evidence that the high activity and selectivity of 2H-MoTe arise from the proper binding energies of HOO and O at its zigzag edges that jointly favor the two-electron reduction instead of the four-electron reduction of molecular oxygen.
分子氧的双电子还原是实现过氧化氢绿色、温和且按需合成的有效策略。然而，其实际可行性取决于先进电催化剂的开发，这种催化剂最好由非贵金属元素组成，以选择性地加速该反应，特别是在酸性介质中。我们在此的研究首次引入2H-MoTe作为在酸性条件下电化学产过氧化氢的高效非贵金属基电催化剂。我们表明，剥离的2H-MoTe纳米片具有高活性（起始过电位约140 mV，相对于可逆氢电极在0.4 V时具有27 A g的大质量活性）、高选择性（HO百分比高达93%）以及在0.5 M HSO中的良好稳定性。理论模拟证明，2H-MoTe的高活性和选择性源于其锯齿边缘处HOO和O的适当结合能，这共同有利于分子氧的双电子还原而非四电子还原。
