Wang Qiheng, Chen Jingkun, Fu Jingbo, Wang Ju, Xing Zhijun, Liu Jingjun
Beijing Key Laboratory of Electrochemical Process and Technology for Materials, Beijing University of Chemical Technology, Beijing, 100029, China.
Changchun Gold Research Institute Co. Ltd, Changchun, 130012, China.
Small. 2025 Jul;21(30):e2503999. doi: 10.1002/smll.202503999. Epub 2025 May 24.
Ordered platinum (Pt) intermetallic compounds with high performance expression under proton exchange membrane fuel cell (PEMFC) operating conditions are a prerequisite for practical application. However, the heat treatment required for forming an ordered structure can lead to severe agglomeration and uneven distribution of nanoparticles, posing a significant challenge to efficient synthesis. Here, a molybdenum (Mo) assisted structural evolution strategy to controllably synthesize sub-4 nm PtCo intermetallic compounds is proposed. The results of experiments combined with density functional theory calculations demonstrate that the participation of trace Mo (0.2 wt.%) not only triggers the "growth site locking effect" and effectively suppresses the growth of nanoparticles, but also effectively adjusts the electronic structure, thereby optimizing the adsorption/desorption of oxygen intermediates. The preeminent intrinsic activity on an optimized catalyst reaches a mass activity as high as 1.22 A mg and has extraordinary stability with only a 5.7% decrease after 30 k cycles. This study paves a new path for the practical application of low Pt catalysts in PEMFCs in the future.
在质子交换膜燃料电池（PEMFC）运行条件下具有高性能表现的有序铂（Pt）金属间化合物是实际应用的前提条件。然而，形成有序结构所需的热处理会导致纳米颗粒严重团聚和分布不均，这对高效合成构成了重大挑战。在此，提出了一种钼（Mo）辅助的结构演化策略，以可控地合成亚4纳米的PtCo金属间化合物。实验结果与密度泛函理论计算相结合表明，痕量Mo（0.2 wt.%）的参与不仅引发了“生长位点锁定效应”并有效抑制了纳米颗粒的生长，还有效调整了电子结构，从而优化了氧中间体的吸附/解吸。优化后的催化剂具有卓越的本征活性，质量活性高达1.22 A mg ，并且具有非凡的稳定性，在30 k次循环后仅下降5.7%。该研究为未来低Pt催化剂在PEMFC中的实际应用开辟了一条新途径。
