Synthesis of highly ordered Al-Zr-SBA-16 composites and their application in dibenzothiophene hydrodesulfurization

Serial Al-Zr-SBA-16 composites are successfully prepared through a two-step synthetic method. The influences of Al and Zr species on the properties of Al-Zr-SBA-16 composites and NiMo corresponding catalysts are investigated by various measurements. The results showed that a series of Al-Zr-SBA-16 supports maintained the intact structure and highly ordered degree. Al and Zr modification could increase the proportion of inactive Mo (Td) and Mo(Oh) species, respectively. The DBT HDS evaluation results revealed that NiMo/AZ-2.5 presented the highest HDS efficiency of 96.2%. The reasons should be ascribed to the factors that the higher dispersion degree of active metals, the highest proportion of MoS2 and NiMoS active phases over NiMo/AZ-2.5 sulfide catalyst, and the highest selectivity of hydrogenation (HYD) route. In addition, principle of hierarchical reaction steps in HYD route was also proposed to explain the reason why the HYD/DDS (direct desulfurization) ratio and HDS efficiency were the highest for NiMo/AZ-2.5 catalyst.