Zeng Zhiqiang, Küspert Sven, Balaghi S Esmael, Hussein Haytham E M, Ortlieb Niklas, Knäbbeler-Buß Markus, Hügenell Philipp, Pollitt Stephan, Hug Niclas, Melke Julia, Fischer Anna
Institute of Inorganic and Analytical Chemistry (IAAC), University of Freiburg, Albertstraße 21, 79104, Freiburg, Germany.
Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Straße 21, 79104, Freiburg, Germany.
Small. 2023 Jul;19(29):e2205885. doi: 10.1002/smll.202205885. Epub 2023 Mar 22.
Platinum is one of the best-performing catalysts for the hydrogen evolution reaction (HER). However, high cost and scarcity severely hinder the large-scale application of Pt electrocatalysts. Constructing highly dispersed ultrasmall Platinum entities is thereby a very effective strategy to increase Pt utilization and mass activities, and reduce costs. Herein, highly dispersed Pt entities composed of a mixture of Pt single atoms, clusters, and nanoparticles are synthesized on mesoporous N-doped carbon nanospheres. The presence of Pt single atoms, clusters, and nanoparticles is demonstrated by combining among others aberration-corrected annular dark-field scanning transmission electron microscopy, X-ray absorption spectroscopy, and electrochemical CO stripping. The best catalyst exhibits excellent geometric and Pt HER mass activity, respectively ≈4 and 26 times higher than that of a commercial Pt/C reference and a Pt catalyst supported on nonporous N-doped carbon nanofibers with similar Pt loadings. Noteworthily, after optimization of the geometrical Pt electrode loading, the best catalyst exhibits ultrahigh Pt and catalyst mass activities (56 ± 3 A mg and 11.7 ± 0.6 A mg at -50 mV vs. reversible hydrogen electrode), which are respectively ≈1.5 and 58 times higher than the highest Pt and catalyst mass activities for Pt single-atom and cluster-based catalysts reported so far.
铂是析氢反应（HER）中性能最佳的催化剂之一。然而，高成本和稀缺性严重阻碍了铂电催化剂的大规模应用。因此，构建高度分散的超小铂实体是提高铂利用率和质量活性并降低成本的非常有效的策略。在此，在介孔氮掺杂碳纳米球上合成了由铂单原子、团簇和纳米颗粒的混合物组成的高度分散的铂实体。通过结合像差校正环形暗场扫描透射电子显微镜、X射线吸收光谱和电化学CO脱附等方法证明了铂单原子、团簇和纳米颗粒的存在。最佳催化剂表现出优异的几何活性和铂析氢质量活性，分别比具有相似铂负载量的商业铂/碳参比催化剂和负载在无孔氮掺杂碳纳米纤维上的铂催化剂高约4倍和26倍。值得注意的是，在优化几何铂电极负载后，最佳催化剂表现出超高的铂和催化剂质量活性（相对于可逆氢电极在-50 mV时为56±3 A mg和11.7±0.6 A mg），分别比迄今为止报道的基于铂单原子和团簇的催化剂的最高铂和催化剂质量活性高约1.5倍和58倍。
