Abstract Pulse and static hydrogen and oxygen chemisorption techniques for determining the platinum dispersion in bimetallic Pt–Sn catalysts were carried out and compared for a monometallic Pt/Al2O3 catalyst and a series of coimpregnated Pt–Sn catalysts containing 1 wt.% of Pt. The pulse chemisorption method gave lower uptakes of hydrogen and oxygen compared to the static volumetric chemisorption method. The differences in hydrogen and oxygen gas uptake behavior can be attributed to the different equilibration times provided by the two chemisorption methods. In the coimpregnated catalyst series, the O/Pt ratio increased with increasing Sn content. The H/Pt ratio, on the other hand, reached the maximum value at 0.1 wt.% Sn. Pulse chemisorption was then used to evaluate how the preparation method affects platinum dispersion and chemisorption behavior. The alumina-supported catalyst series prepared by coimpregnation of Pt and Sn was compared with a series of catalysts prepared by sequential impregnation with tin first, followed by platinum as second component. Coimpregnation of the Al2O3 support with platinum and small amounts of tin facilitates high Pt dispersion, while sequential impregnation of the support with Sn first, followed by Pt, leads to much lower Pt dispersion.

中文翻译：

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Pt-Sn/Al2O3 催化剂：催化剂制备和化学吸附方法对 H2 和 O2 吸收的影响

摘要 采用脉冲和静态氢氧化学吸附技术测定双金属 Pt-Sn 催化剂中铂的分散度，并对单金属 Pt/Al2O3 催化剂和一系列含 1 wt.% Pt 的共浸渍 Pt-Sn 催化剂进行了比较。与静态体积化学吸附法相比，脉冲化学吸附法对氢气和氧气的吸收量较低。氢气和氧气吸收行为的差异可归因于两种化学吸附方法提供的不同平衡时间。在共浸渍催化剂系列中，O/Pt 比随着 Sn 含量的增加而增加。另一方面，H/Pt 比在 0.1 wt.% Sn 时达到最大值。然后使用脉冲化学吸附来评估制备方法如何影响铂分散和化学吸附行为。将由 Pt 和 Sn 共浸渍制备的氧化铝负载催化剂系列与先用锡顺序浸渍制备的一系列催化剂进行了比较，然后用铂作为第二组分。Al2O3 载体与铂和少量锡的共浸渍有利于 Pt 的高分散，而载体首先用 Sn 依次浸渍，然后是 Pt，导致 Pt 分散度低得多。