Cai Jialin, Chen Junxiang, Chen Yizhe, Zhang Jiujun, Zhang Shiming
Institute for Sustainable Energy/College of Sciences, Shanghai University, Shanghai 200444, China.
State Key Laboratory of Structural Chemistry, and CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
iScience. 2023 Apr 24;26(5):106730. doi: 10.1016/j.isci.2023.106730. eCollection 2023 May 19.
Innovation of catalyst structure is extremely important to develop the high-performance electrocatalysts for oxygen-reduction reaction (ORR). Herein, nitrogen-doped carbon semi-tube (N-CST) is used as a functional support for stabilizing the microwave-reduced Pt nanoparticles with an average size of ∼2.8 nm to synthesize the semi-tubular Pt/N-CST catalyst. The contribution of interfacial Pt-N bond between N-CST support and Pt nanoparticles with electrons transfer from N-CST support to Pt nanoparticles is found by electron paramagnetic resonance (EPR) and X-ray absorption fine structure (XAFS) spectroscopy. This bridged Pt-N coordination can simultaneously help ORR electrocatalysis and promote electrochemical stability. As a result, the innovative Pt/N-CST catalyst exhibits excellent catalytic performance, realizing ORR activity and electrochemical stability superior to the commercial Pt/C catalyst. Furthermore, density functional theoretical (DFT) calculations suggest that the interfacial Pt-N-C site with unique affinity of O∗ + OH∗ can provide new active routes for the enhanced electrocatalytic ORR capacity.
催化剂结构的创新对于开发用于氧还原反应（ORR）的高性能电催化剂极为重要。在此，氮掺杂碳半管（N-CST）用作功能载体，以稳定平均尺寸约为2.8 nm的微波还原Pt纳米颗粒，从而合成半管状Pt/N-CST催化剂。通过电子顺磁共振（EPR）和X射线吸收精细结构（XAFS）光谱发现了N-CST载体与Pt纳米颗粒之间界面Pt-N键的贡献以及电子从N-CST载体转移到Pt纳米颗粒的过程。这种桥连的Pt-N配位可以同时助力ORR电催化并促进电化学稳定性。结果，创新的Pt/N-CST催化剂表现出优异的催化性能，实现了优于商业Pt/C催化剂的ORR活性和电化学稳定性。此外，密度泛函理论（DFT）计算表明，具有独特O∗ + OH∗亲和力的界面Pt-N-C位点可为增强的电催化ORR能力提供新的活性途径。
