Porous spherical γ-alumina supports play the key role in the petroleum reforming industry with strict requirement in hydrothermal stability of pore structure. Here, a series of pseudo-boehmite samples with different crystal orientations were synthesized in a separate nucleation and aging steps method by adjusting the rotating speed. The pseudo-boehmite (PB-1000) at 1000 rpm yields a high (020) plane proportion of 44.52 %, which is comparable with that of 43.91 % for the Sasol Boehmite (SB) powder. The AlO-1000 from the PB-1000 demonstrated the highest content of γ-AlO phase, the lowest surface hydroxyl number of 1.56/nm, and the highest hydrothermal stability with the retention rate of 75.0 % (174 m·g) at 600 °C under water vapor for 120 h, which is comparable to that of 72.3 % (191 m·g) for the Sasol sample. It is the first time to investigate hydrothermal stability of alumina from the content of γ-AlO phase and the surface hydroxyl groups.

中文翻译：

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γ-Al2O3 载体的水热稳定性随拟薄水铝石前驱体晶面取向的变化而变化

多孔球形γ-氧化铝载体在石油重整工业中发挥着关键作用，对孔结构的水热稳定性要求严格。在这里，通过调节转速，以单独的成核和老化步骤方法合成了一系列具有不同晶体取向的拟薄水铝石样品。假勃姆石 (PB-1000) 在 1000 rpm 下产生 44.52% 的高 (020) 平面比例，与 Sasol 勃姆石 (SB) 粉末的 43.91% 相当。 PB-1000 中的 Al2O-1000 表现出最高的 γ-Al2O 相含量、最低的表面羟基数（1.56/nm）和最高的水热稳定性，在 600 ° 时保留率为 75.0 % (174 m·g) C 在水蒸气下持续 120 小时，与 Sasol 样品的 72.3 % (191 m·g) 相当。首次从γ-Al2O相含量和表面羟基角度研究氧化铝的水热稳定性。