Abstract:
A series of Cu/ZnO/Al
2O
3 catalysts were prepared by co-precipitation method. This research focuses on investigating the influence of different Al
2O
3 precursors on the catalyst structure through thorough structural characterization techniques. Additionally, the catalytic performance of these catalysts in methanol reforming for hydrogen production was systematically evaluated. The results indicate that the simultaneous co-precipitation of Al
3+ with Cu
2+ and Zn
2+ leads to partial substitution of Cu-Zn in the basic carbonates by Al
3+. This substitution forms a hydrotalcite-like structure and strengthens Zn-Al interactions. On the contrary, after the co-precipitation of Cu
2+ and Zn
2+, introducing the Al
2O
3 precursor has a positive effect on eliminating the adverse effects of Al
3+ on Cu-Zn substitution in basic carbonates. This process promotes the Cu-ZnO interaction, facilitates the dispersion of CuO species, and enhances the reducibility of catalysts. It also improves the dispersion of Cu on the surface, and ultimately enhanced the catalytic activity. Notably, the catalyst prepared using pseudo-boehmite as the Al
2O
3 precursor exhibited the highest activity. Under the conditions of a H
2O/CH
3OH molar ratio of 1.2 and a reaction temperature of 493 K, methanol conversion reached 94.8%, and the H
2 space-time yield was 97.5 mol/(kg·h). The catalyst activity remained relatively stable after continuous operation for 25 h. Even after being heat-treated at 723 K for 10 h, the activity loss of the catalyst was only 5.37%.