Mesoporous yolk-shell silica spheres with different shell thicknesses and yolk sizes (YxSy) were synthesized by incubating mesostructured nanospheres water. Al-modified YxSy-supported NiMo catalysts prepared applied to hydrodesulfurization (HDS) of dibenzothiophene (DBT) 4,6-dimethyldibenzothiophene (4,6-DMDBT). The thickness size have a large effect on the HDS activities. Among as-made catalys...