Lu Shaojie, Hu Yiping, Xia Fanjie, Yang Shaokang, Jiang Shuaihu, Zhou Yu, Ma Dongsheng, Zhang Wenjing, Li Jing, Wu Jinsong, Rao Dewei, Yue Qin
Institute of Fundamental and Frontier Science, University of Electronic Science and Technology of China, Chengdu, 610054, China.
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, NRC (Nanostructure Research Centre) Wuhan University of Technology, Wuhan, 430070, China.
Small. 2024 Apr;20(15):e2305296. doi: 10.1002/smll.202305296. Epub 2023 Nov 27.
Developing a highly active, durable, and low-platinum-based electrocatalyst for the cathodic oxygen reduction reaction (ORR) is for breaking the bottleneck of large-scale applications of proton exchange membrane fuel cells (PEMFCs). Herein, ultrafine PtZn intermetallic nanoparticles with low Pt-loading and trace germanium (Ge) involvement confined in the nitrogen-doped porous carbon (Ge-L-PtZn@N-C) are reported. The Ge-L-PtZn@N-C exhibit superior ORR activity with a mass activity of 3.04 A mg and specific activity of 4.69 mA cm, ≈12.2- and 10.2-times improvement compared to the commercial Pt/C (20%) at 0.90 V in 0.1 m KOH. The cathodic catalyst Ge-L-PtZn@N-C assembled in the PEMFC shows encouraging peak power densities of 316.5 (at 0.86 V) and 417.2 mW cm (at 0.91 V) in alkaline and acidic fuel-cell, respectively. The combination of experiment and density functional theory calculations (DFT) results robustly reveal that the participation of trace Ge can not only trigger a "growth site locking effect" to effectively inhibit nanoparticle growth, bring miniature nanoparticles, enhance dispersion uniformity, and achieve the exposure of the more electrochemical active site, but also effectively modulates the electronic structure, hence optimizing the adsorption/desorption of the oxygen intermediates.
开发一种用于阴极氧还原反应（ORR）的高活性、耐用且低铂基的电催化剂，是为了突破质子交换膜燃料电池（PEMFC）大规模应用的瓶颈。在此，报道了一种负载低铂且含有痕量锗（Ge）的超细PtZn金属间化合物纳米颗粒，其被限制在氮掺杂多孔碳（Ge-L-PtZn@N-C）中。在0.1 m KOH中，0.90 V时，Ge-L-PtZn@N-C表现出优异的ORR活性，质量活性为3.04 A mg ，比活性为4.69 mA cm ，与商业Pt/C（20%）相比，分别提高了约12.2倍和10.2倍。组装在PEMFC中的阴极催化剂Ge-L-PtZn@N-C在碱性和酸性燃料电池中分别显示出令人鼓舞的峰值功率密度，在碱性燃料电池中为316.5（在0.86 V时），在酸性燃料电池中为417.2 mW cm （在0.91 V时）。实验和密度泛函理论计算（DFT）结果相结合有力地表明，痕量Ge的参与不仅可以引发“生长位点锁定效应”，有效抑制纳米颗粒生长，产生微型纳米颗粒，提高分散均匀性，并实现更多电化学活性位点的暴露，还能有效调节电子结构，从而优化氧中间体的吸附/解吸。
