Grain‐Boundary‐Rich Noble Metal Nanoparticle Assemblies: Synthesis, Characterization, and Reactivity
Grain‐Boundary‐Rich Noble Metal Nanoparticle Assemblies: Synthesis, Characterization, and Reactivity
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DOI：
10.1002/adfm.202204169
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发表时间：
2022-06
影响因子：
19
通讯作者：
X. Geng;Shuwei Li;Jaeyoung Heo;Yi Peng;Wenhui Hu;Yanchao Liu;Jier Huang;Yang Ren;
中科院分区：
文献类型：
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作者：
X. Geng;Shuwei Li;Jaeyoung Heo;Yi Peng;Wenhui Hu;Yanchao Liu;Jier Huang;Yang Ren;
在这里，提出了对富晶界（GB）贵金属纳米颗粒（NP）组装体的合成、表征和反应性的全面研究。开发了Pt、Pd、Au、Ag和Rh NP组装体的简易且可规模化的合成，其中NP主要通过113（111）双GB连接，形成网络。在水电解的驱动下，纳米粒子在溶液中的随机碰撞和定向附着导致了纳米粒子间的相互作用，从而形成了纳米粒子间的113（111）孪晶界和一些高度失配的晶界。该合成方法还提供了对GB密度的方便控制，而不通过改变NP碰撞频率来改变微晶尺寸或GB类型。结构表征揭示了在GB站点存在局部拉伸应变。证明了富含GB的Pt NP组装体对空气中催化氢氧化的催化活性，首次实现了室温催化氢传感。最后，密度泛函理论计算表明，应变的ε 3（111）孪晶界促进氧的解离，大大提高氢的氧化速率通过解离途径。这一报道的大规模合成的β 3（111）双富GB结构使得能够开发广泛的高性能富GB催化剂。
Here, a comprehensive study on the synthesis, characterization, and reactivity of grain‐boundary (GB)‐rich noble metal nanoparticle (NP) assemblies is presented. A facile and scalable synthesis of Pt, Pd, Au, Ag, and Rh NP assemblies is developed, in which NPs are predominantly connected via Σ3 (111) twin GBs, forming a network. Driven by water electrolysis, the random collisions and oriented attachment of colloidal NPs in solution lead to the formation of Σ3 (111) twin boundaries and some highly mismatched GBs. This synthetic method also provides convenient control over the GB density without altering the crystallite size or GB type by varying the NP collision frequency. The structural characterization reveals the presence of localized tensile strain at the GB sites. The ultrahigh activity of GB‐rich Pt NP assembly toward catalytic hydrogen oxidation in air is demonstrated, enabling room‐temperature catalytic hydrogen sensing for the first time. Finally, density functional theory calculations reveal that the strained Σ3(111) twin boundary facilitates oxygen dissociation, drastically enhancing the hydrogen oxidation rate via the dissociative pathway. This reported large‐scale synthesis of the Σ3 (111) twin GB‐rich structures enables the development of a broad range of high‐performance GB‐rich catalysts.