Modified hierarchical Y Zeolite: A Novel Strategy for Enhanced Desulfurization Process

Hierarchical HY zeolite (Hei-Y) with SiO۲/Al۲O۳ molar ratios of ۱۰ was successfully achieved by sequential desilication-dealumination using NH۴OH treatment. Metal oxides (CuO, MoO۳)- hierarchical HY zeolite nanocomposites were prepared via one or all of ۳ steps: ۱) ion exchange, ۲) precipitation, and ۳) calcination method. The obtained catalysts were characterized using XRD, FT-IR, FESEM, UV-Vis, EDS and BET techniques. Hierarchical zeolite formation is accompanied by structure preservation, however, by entering Cu in the zeolite porous, slight destruction is observed. The catalytic activity of catalysts was investigated in oxidative desulfurization (ODS) and the progress of the reaction was studied by GC. The effect of several parameters including temperature, catalyst amount, DBT concentration, and reaction time on ODS was studied using Taguchi software. The order of catalytic activity was obtained as follows: Y < Hei-Y < Hei-Y /CuO-Hei < MoO۳-Hei < CuO/MoO۳- Hei-Y. The results showed that the activity of the CuO/MoO۳-Hei-Y hierarchical structure has increased due to their synergistic effects based on the presence of secondary mesoporosity and metal oxides. The catalyst is recoverable and was reused for five consecutive runs.