In this study, unique mesoporous structure alumina microspheres, each of which comprises an assembly of numerous highly crystallized alumina nanorods, were prepared via a facile template-free hydrothermal method. Such alumina microspheres were further assembled in one step to form a macroporous structure with abundant inter-microspheres via pore-directing-agent-free molding process. Owing to the morphological merits and the remarkable mechanical stability of the as-formed alumina microspheres, the macropores formed from the stable packing of the alumina microspheres had average sizes as large as 265 nm and were well connected with each other. Moreover, the inter-microsphere mesopores with an average size of 12.2 nm were well-maintained after the molding process. With such hierarchical porosity and large specific surface area, the as-prepared alumina support enabled better dispersion of the active MoNi components. Accordingly, the macro–mesoporous MoNi/Al₂O₃ catalyst exhibited both significantly higher catalytic activities and longer service life for the hydrodemetallization of nickel(II) 5, 10, 15, 20-tetraphenylporphine and for the hydrodesulfurization of dibenzothiophene as compared to controls with a single type of pores. With the ease of preparation, large surface area, and remarkable activity and stability, such a macro–mesoporous alumina support provides a promising alternative for hydrotreating heavy raw oils in industry.

中文翻译：

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迈向活性大中孔加氢处理催化剂：介孔氧化铝微球的合成和组装†

在这项研究中，通过简便的无模板水热法制备了独特的介孔结构氧化铝微球，每个微球都包含许多高度结晶的氧化铝纳米棒的组件。这样的氧化铝微球在一步中被进一步组装以形成具有丰富的微球间的大孔结构，通过无孔定向剂的成型工艺。由于所形成的氧化铝微球的形态学优点和出色的机械稳定性，由氧化铝微球的稳定堆积形成的大孔的平均尺寸大至265nm，并且彼此良好地连接。此外，在模制过程之后，平均尺寸为12.2 nm的微球间中孔得到了良好的维护。由于具有这种分级的孔隙率和大的比表面积，所制备的氧化铝载体能够使活性MoNi组分更好地分散。因此，宏观孔MONI / Al的₂ ö ₃催化剂显示出对镍的加氢脱金属二者显著更高的催化活性和更长的使用寿命（II）5、10、15、20-四苯基卟啉与二苯并噻吩的加氢脱硫相比，与具有单一类型孔的对照组相比。由于易于制备，大表面积，出色的活性和稳定性，这种介孔的氧化铝载体为工业中重质粗油的加氢处理提供了有希望的替代方法。