Pt/Al₂O₃ catalysts with different Pt particle sizes and after phosphorous deposition were studied for liquid phase catalysed furfural hydrogenation. The activity and selectivity were related to various physico-chemical properties studied by scanning transmission electron microscopy, N₂ physisorption, ³¹P nuclear magnetic resonance, diffuse reflectance Fourier transform infrared spectroscopy and attenuated total reflectance infrared spectroscopy. The results indicate that the large particles obtained upon calcination of 1 wt% Pt/Al₂O₃ at 600 °C exhibited higher turnover frequency per surface Pt; nonetheless, the overall activity decreased due to the loss of surface Pt upon sintering. While in certain cases phosphorous can act as promoter, the addition of this element to Pt/Al₂O₃ resulted in catalyst poisoning, which was ascribed to Pt encapsulation/blockage effects related to formation of AlPO₄. Finally, gradual deactivation of Pt/Al₂O₃ was observed over five consecutive catalytic cycles which was caused by Pt sintering (from 0.6 to 2.0 nm) as well as by irreversible adsorption of organic reaction intermediates.

Graphic Abstract

中文翻译：

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Pt粒径和磷添加量对Pt/Al2O3上糠醛加氢反应的影响

研究了具有不同 Pt 粒径和磷沉积后的Pt/Al ₂ O ₃催化剂用于液相催化糠醛氢化。活性和选择性与通过扫描透射电子显微镜、N ₂物理吸附、³¹ P 核磁共振、漫反射傅里叶变换红外光谱和衰减全反射红外光谱研究的各种理化性质有关。结果表明，1 wt% Pt/Al ₂ O ₃煅烧得到的大颗粒在 600 °C 时，每个表面 Pt 表现出更高的周转频率；尽管如此，由于烧结时表面 Pt 的损失，整体活性降低。虽然在某些情况下磷可以作为促进剂，但将这种元素添加到 Pt/Al ₂ O _{3 中会}导致催化剂中毒，这归因于与形成 AlPO ₄相关的 Pt 包封/阻塞效应。最后，在连续五个催化循环中观察到Pt/Al ₂ O ₃逐渐失活，这是由 Pt 烧结（从 0.6 到 2.0 nm）以及有机反应中间体的不可逆吸附引起的。

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