Length Roles of Al2O3 coating layer on an ordered mesoporous Ni/m-Al2O3 for combined steam and CO2 reforming with CH4

To enhance catalytic and thermal stability of Ni nanoparticles for a combined steam and CO2 reforming with CH4 (CSCR), the utilization of an ordered mesoporous Al2O3 support with-6 nm of average pore diameter (Ni/m-Al) was proposed in terms of spatial confinement effects of the Ni nanoparticles with the help of successive Al2O3 overlayer protective layers (Ni/m-Al@Al). At an optimal amount of Al2O3 coating layers less than-3 wt%, the much higher catalytic activity and stability were observed on the Ni/m-Al@Al(3). The synergy effects of Al2O3 overlayers on the ordered mesoporous Ni/m-Al were mainly attributed to the formation of strongly interacted Ni-Al2O3 interfaces as supported by its higher XPS binding energy in the spatially restricted mesoporous m-Al channels with the protective metal oxide overlayers. Those structures were also responsible for the suppressed migrations of the spatially confined Ni nanoparticles to the outer m-Al surfaces by Al2O3 protective overlayers, which resulted in an excellent long-term stability with small coke depositions by preserving the original Ni nanoparticle sizes. Superscript/Subscript Available

Automated summary

In this study, the catalytic and thermal stability of Ni nanoparticles were enhanced by using an ordered mesoporous Al2O3 support and successive Al2O3 protective layers. This resulted in improved catalytic activity and stability for steam and CO2 reforming with CH4 (CSCR). The synergy effects of the Al2O3 overlayers on the ordered mesoporous Ni/m-Al were attributed to the formation of strongly interacted Ni-Al2O3 interfaces, which restricted the migrations of the Ni nanoparticles and preserved their original sizes.