Molar-Fraction-Tunable Synthesis of Ag-Au Alloy Nanoparticles via a Dual Evaporation-Condensation Method as Supported Catalysts for CO Oxidation
Molar-Fraction-Tunable Synthesis of Ag-Au Alloy Nanoparticles via a Dual Evaporation-Condensation Method as Supported Catalysts for CO Oxidation
复制标题
通过双重蒸发-缩合法摩尔分数可调合成银-金合金纳米颗粒作为 CO 氧化负载催化剂
DOI：
10.1021/acsanm.3c00089
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发表时间：
2023
影响因子：
5.9
通讯作者：
Sakono Masafumi
中科院分区：
文献类型：
--
作者：
Sakono Naomi;Ishida Yuto;Ogo Kazuki;Tsumori Nobuko;Murayama Haruno;Sakono Masafumi
由两种金属元素组成的纳米颗粒的性质受到它们的协同作用以及纳米晶体的组成和结构的影响。因此，为了成功合成，需要精确调节组成元素的摩尔分数和晶体结构。一种代表气溶胶纳米颗粒合成方法的蒸发-冷凝方法是基于气相中金属元素的再团聚。在这项研究中，我们利用双蒸发冷凝法与两个炉调整的摩尔分数的银-金纳米粒子与合金型纳米晶结构，并获得球形粒子的尺寸小于10 nm。在合成的颗粒中的Ag原子的摩尔分数在0和80%之间变化，这取决于加热温度。能量色散X射线光谱数据显示，Ag和Au元素存在于所有颗粒中并形成合金结构，表明通过双蒸发-冷凝法可以容易地制备具有不同化学计量比的合金化复合颗粒。此外，在气相中产生的纳米粒子被成功地回收固定在基板上，并作为有效的CO2催化剂的CO氧化。值得注意的是，在所提出的方法中，纳米颗粒的制备及其固定到基底上是在一个步骤中进行的。
The properties of nanoparticles composed of two metallic elements are affected by their synergy as well as the composition and structure of nanocrystals. Therefore, precise adjustment of the molar fractions of the constituent elements and crystal structure is required for their successful synthesis. An evaporation–condensation method, which represents an aerosol nanoparticle synthesis method, is based on the reagglomeration of metallic elements in the gas phase. In this study, we utilized a dual evaporation–condensation method with two furnaces to adjust the molar fractions of Ag–Au nanoparticles with an alloy-type nanocrystalline structure and obtain spherical particles with sizes smaller than 10 nm. The molar fraction of Ag atoms in the synthesized particles varied between 0 and 80% depending on the heating temperature. Energy-dispersive X-ray spectroscopy data revealed that Ag and Au elements were present in all particles and formed an alloy structure, suggesting that alloyed composite particles with different stoichiometries can be easily fabricated via the dual evaporation–condensation method. In addition, the nanoparticles generated in the gas phase were successfully recovered by immobilization on a substrate and served as effective bimetallic catalysts for CO oxidation. It is noteworthy that the preparation of nanoparticles and their fixation to a substrate in the proposed method were performed in one step.