Nanoparticulate gold supported on a Keggin‐type polyoxometalate (POM), Cs₄[α‐SiW₁₂O₄₀]⋅n H₂O, was prepared by the sol immobilization method. The size of the gold nanoparticles (NPs) was approximately 2 nm, which was almost the same as the size of the gold colloid precursor. Deposition of gold NPs smaller than 2 nm onto POM (Au/POM) was essential for a high catalytic activity for CO oxidation. The temperature for 50 % CO conversion was −67 °C. The catalyst showed extremely high stability for at least one month at 0 °C with full conversion. The catalytic activity and the reaction mechanism drastically changed at temperatures higher than 40 °C, showing a unique behavior called a U‐shaped curve. It was revealed by IR measurement that Au^δ+ was a CO adsorption site and that adsorbed water promoted CO oxidation for the Au/POM catalyst. This is the first report on CO oxidation utilizing Au/POMs catalysts, and there is a potential for expansion to various gas‐phase reactions.

中文翻译：

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多金属氧酸盐负载的金纳米颗粒催化剂对一氧化碳的氧化作用：活性，稳定性和随温度变化的活化特性

支撑在Keggin型多金属氧酸盐（POM），CS纳米颗粒金₄ [α-硅钨酸₁₂ ö ₄₀ ]⋅ Ñ  ħ ₂通过溶胶固定法制备O。金纳米颗粒（NP）的大小约为2 nm，几乎与金胶体前体的大小相同。将小于2 nm的金纳米颗粒沉积到POM（Au / POM）上对于CO氧化的高催化活性至关重要。50％CO转化的温度为-67℃。该催化剂在0°C下具有至少一个月的极高稳定性，并具有完全转化率。在高于40°C的温度下，催化活性和反应机理发生了巨大变化，显示出一种独特的行为，称为U形曲线。通过红外测量发现Auδ ⁺是CO的吸附位点，并且吸附的水促进了Au / POM催化剂的CO氧化。这是有关使用Au / POMs催化剂进行CO氧化的第一份报告，并且有扩展到各种气相反应的潜力。