Highly Dispersed Nickel Nanoparticles on Hierarchically Ordered Macroporous Al2O3 and Its Catalytic Performance for Steam Reforming of 1-Methyl Naphthalene

In this study, we investigate the effect of a hierarchically ordered macroporous structure of alumina support on the steam reforming of 1-methyl naphthalene with mesoporous alumina-supported nickel and potassium (xK/Ni-MeAl), and macroporous alumina-supported nickel and potassium (xK/Ni-MaAl) catalysts. Hierarchically ordered macroporosity in Al2O3 supports plays an important role in maintaining the high Ni dispersion through multiple interactions in Ni-K over AlO4 tetrahedra in alumina. This, in turn, improves the catalytic performance of steam reforming, including high gas yields, turnover frequency for hydrogen production, and 1-methyl naphthalene conversion. At high K content, the Ni active sites over xK/Ni-MeAl catalysts significantly decrease, resulting in almost zero steam reforming rate in the reaction test. Conversely, the potassium-alumina interaction in xK/Ni-MaAl catalysts not only diminishes the formation of the inactive nickel aluminate phase but also maintains the highly dispersed Ni active sites, resulting in a high steam reforming rate.

Automated summary

In this study, the effect of hierarchically ordered macroporous structure of alumina support on the catalytic performance of steam reforming was investigated. The results showed that the hierarchically ordered macroporosity can maintain high Ni dispersion and improve the catalytic performance. At high potassium content, the decrease in Ni active sites resulted in a decrease in steam reforming rate. However, the potassium-alumina interaction can diminish the formation of inactive phases and maintain highly dispersed Ni active sites, leading to a high steam reforming rate.