“…The presence of macropores in mesoporous alumina is important and useful especially for the treatment of bulky molecules, because textural mesopores and interconnected macropores should efficiently transport guest species to framework binding sites . For example, in the hydrocracking reaction of residue from Athabasca bitumen , a catalyst containing 15% of alumina that has macropores (0.1−100 μm) gave larger +525 °C conversion, higher yields of distillates, and greater total product hydrodesulfurization, hydrodenitrogenation, and microcarbon residue conversion as compared to a standard reference catalyst . Very recently, Rambo and co-worker synthesized biomorphic α-Al 2 O 3 ceramics via three consecutive high-temperature processes: pyrolysis of rattan in nitrogen atmosphere (800 °C), Al-vapor infiltration in a vacuum (1200−1600 °C) and oxidation/sintering (1600 °C) …”