Synthesis of high surface area MgAl2O4 spinel as catalyst support via layered double hydroxides-containing precursor

Abstract Magnesium aluminate spinel (MgAl 2 O 4 ) was synthesized via layered double hydroxides (LDHs)-containing precursor by co-precipitation method. The precursors and the calcined powders were characterized by various techniques including N 2 physical adsorption, powder X-ray diffraction (XRD), 27 Al nuclear magnetic resonance (NMR), thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The characterization results suggested that the as -synthesized precursor was mainly composed of Mg Al LDHs and gibbsite Al(OH) 3 . Upon calcination of the LDHs-containing precursor at 600 ~ 700 °C, MgAl 2 O 4 spinel was formed and a high BET specific surface area of ~ 193 m 2 g − 1 was achieved at 700 °C, demonstrating the effectiveness of LDHs-containing precursor for the preparation of high surface area MgAl 2 O 4 spinel. It was suggested that the poorly crystalline Mg(Al)O solid solution resulted from the thermal decomposition of Mg Al LDHs might facilitate the formation of MgAl 2 O 4 spinel. The precipitation procedure had significant effect on the textural property of spinel. The MgAl 2 O 4 prepared by constant pH precipitation exhibited much higher BET specific surface area than those prepared by decreasing pH precipitation and increasing pH precipitation. This high-surface area MgAl 2 O 4 appeared a promising catalyst support. The prepared MgAl 2 O 4 -supported Ni catalyst possessed well-dispersed Ni nanoparticles and exhibited stable activity for the carbon dioxide reforming of methane.