Abstract

The study is presented on the influence of the composition of a ceria-zirconia support on the structure and the activity in water-gas shift reaction of platinum catalysts (Pt/Ce_0.75Zr_0.25O₂ and Pt/Ce_0.4Zr_0.5Y_0.05La_0.05O₂). The structure diagnostics of the samples were performed using high-resolution transmission electron microscopy, powder X-ray diffraction, CO chemisorption and X-ray atomic pair distribution function method. It was shown that the catalysts contain highly dispersed platinum particles not exceeding 2 nm in size. Platinum particles supported on Ce_0.75Zr_0.25O₂ are smaller due to the higher specific surface area of the support. The catalysts Pt/Ce_0.75Zr_0.25O₂ and Pt/Ce_0.4Zr_0.5Y_0.05La_0.05O₂ proved to have similar efficiency while having the same platinum content. It was assumed that the catalysts supported on Ce_0.4Zr_0.5Y_0.05La_0.05O₂ demonstrate a slightly higher turnover frequency per platinum surface atom, but it is likely compensated by the difference in the supported metal particle size.

中文翻译：

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氧化铈-氧化锆负载的铂催化剂用于水煤气变换反应：载体成分的影响

摘要

_{研究了氧化铈-氧化锆载体的组成对铂催化剂(Pt/Ce 0.75} Zr _0.25 O ₂和Pt/Ce _0.4 Zr _0.5 Y _0.05 La _0.05 O ₂ )结构和水煤气变换反应活性的影响。采用高分辨率透射电子显微镜、粉末X射线衍射、CO化学吸附和X射线原子对分布函数法对样品进行结构诊断。结果表明，该催化剂含有高度分散的尺寸不超过2 nm的铂颗粒。_{Ce 0.75} Zr _0.25 O负载的铂颗粒由于载体的比表面积较高，_2更小。催化剂Pt/Ce _0.75 Zr _0.25 O ₂和Pt/Ce _0.4 Zr _0.5 Y _0.05 La _0.05 O ₂证明在具有相同的铂含量时具有相似的效率。假设负载在Ce _0.4 Zr _0.5 Y _0.05 La _0.05 O ₂上的催化剂表现出稍微较高的每个铂表面原子的周转频率，但这可能通过负载的金属颗粒尺寸的差异来补偿。