In order to fully exploit the green characteristics of solid base catalysts they should be fabricated intomacrostructured rather than powder form. Magnesia-rich magnesium aluminate spinel (MgO • MgAl2O4)framework catalysts with tunable basicity have been prepared by using _-Al2O3 macrospheres (0.5–1.0mmin diameter) as a hard template. The process involves in situ growth of magnesium–aluminum layereddouble hydroxides (MgAl-LDHs) in the channels of the _-Al2O3 macrospheres by the urea hydrolysismethod, followed by calcination, tuning of the basicity through etching of excess aluminum with aqueousalkali and a final calcination step. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmissionelectron microscopy (TEM), high-resolution TEM (HRTEM), elemental analysis and low temperatureN2 adsorption–desorption studies demonstrate that the composite MgO•MgAl2O4 materials are composedof nanosized rod-like particles aggregated into a spherical framework. Catalytic reactivity was investigatedby using methanolysis of soybean oil as probe reaction. The MgO • MgAl2O4 composite shows a higherbiodiesel yield compared to an MgO/MgAl2O4/_-Al2O3 material with the same loading of magnesiumprepared by a conventional impregnation method. The enhanced catalytic activity of the former materialcan be ascribed to its higher basicity, specific surface area, pore volume and pore size.