Zhang Quan, Kusada Kohei, Wu Dongshuang, Yamamoto Tomokazu, Toriyama Takaaki, Matsumura Syo, Kawaguchi Shogo, Kubota Yoshiki, Kitagawa Hiroshi
Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
The Ultramicroscopy Research Centre, Kyushu University, Motooka 744, Nishi-ku, Fukuoka 819-0395, Japan.
J Am Chem Soc. 2022 Mar 9;144(9):4224-4232. doi: 10.1021/jacs.2c00583. Epub 2022 Feb 23.
The crystal structure significantly affects the physical and chemical properties of solids. However, the crystal structure-dependent properties of alloys are rarely studied because controlling the crystal structure of an alloy at the same composition is extremely difficult. Here, for the first time, we successfully demonstrate the synthesis of binary Ru-Pt (Ru/Pt = 7:3) and Ru-Ir (Ru/Ir = 7:3) and ternary Ru-Ir-Pt (Ru/Ir/Pt = 7:1.5:1.5) solid-solution alloy nanoparticles (NPs) with well-controlled hexagonal close-packed (hcp) and face-centered cubic (fcc) phases, through the chemical reduction method. The crystal structure control is realized by precisely tunning the reduction speeds of the metal precursors. The effect of the crystal structure on the catalytic performance of solid-solution alloy NPs is systematically investigated. Impressively, all the hcp alloy NPs show superior electrocatalytic activities for the hydrogen evolution reaction in alkaline solution compared with the fcc alloy NPs. In particular, hcp-RuIrPt exhibits extremely high intrinsic (mass) activity, which is 3.1 (3.2) and 6.7 (6.9) times enhanced compared to that of fcc-RuIrPt and commercial Pt/C.
晶体结构显著影响固体的物理和化学性质。然而，合金的晶体结构依赖性性质很少被研究，因为在相同组成下控制合金的晶体结构极其困难。在此，我们首次通过化学还原法成功地证明了合成具有良好控制的六方密堆积（hcp）和面心立方（fcc）相的二元Ru-Pt（Ru/Pt = 7:3）和Ru-Ir（Ru/Ir = 7:3）以及三元Ru-Ir-Pt（Ru/Ir/Pt = 7:1.5:1.5）固溶体合金纳米颗粒（NPs）。通过精确调节金属前驱体的还原速度实现了晶体结构控制。系统地研究了晶体结构对固溶体合金NPs催化性能的影响。令人印象深刻的是，与fcc合金NPs相比，所有hcp合金NPs在碱性溶液中对析氢反应均表现出优异的电催化活性。特别是，hcp-RuIrPt表现出极高的本征（质量）活性，与fcc-RuIrPt和商业Pt/C相比，分别提高了3.1（3.2）倍和6.7（6.9）倍。
