Aluminum source-assisted synthesis strategy for enhancing ultra-deep desulfurization for thiophene over Cu-ZnO/Al2O3 sorbent

Cu-ZnO is a promising sorbent for the removal of thiophene. However, the aggregation and growth of copper grains during the heating reaction leads to the sintering deactivation of the sorbent. Although various strategies have been proposed to introduce supports to mitigate these defects, the impact of supports on the desulfurization performance of sorbent remains poorly understood. In this study, Cu-ZnO/Al 2 O 3 sorbents were synthesized with excellent performance by incorporating Al 2 O 3 (derived from Al(NO 3 ) 3 , γ-Al 2 O 3 and AlOOH as aluminum sources) using co-precipitation and fractional precipitation methods. The thiophene removal evaluation was conducted in a fixed bed reactor. The results indicates that the breakthrough adsorption capacity for thiophene ( Q b-thiophene ) of sorbent synthesized using γ-Al 2 O 3 and AlOOH is approximately 25 % higher than that of those synthesized with Al(NO 3 ) 3 . In comparison to Al(NO 3 ) 3 , γ-Al 2 O 3 and AlOOH exert less influence on the precipitation and crystallization processes of Cu 2+ and Zn 2+ . Sorbents synthesized with γ-Al 2 O 3 and AlOOH as aluminum sources demonstrate higher copper dispersion, larger specific surface area and smaller grain size, all of which significantly enhance the desulfurization activity of sorbent. Furthermore, the use of γ-Al 2 O 3 and AlOOH as aluminum sources contributes to an increase in ZnO and unsaturated Zn δ+ contents on sorbent surface. This improvement enhances hydrogen storage capacity and promotes hydrogen spillover at the Cu-ZnO interface; additionally, it facilitates both the adsorption activation of thiophene and the stable fixation of sulfur species. These findings provide an important theoretical basis for the design and large-scale application of efficient desulfurization sorbents.