This document summarizes research on the synthesis, characterization, and application of mesoporous niobium and tantalum oxides in heterogeneous catalysis. Mesoporous transition metal oxides were synthesized using a ligand-assisted templating approach with surfactants. Characterization techniques including powder XRD, nitrogen adsorption, SEM, TEM, FT-IR and NMR confirmed the mesoporous structure. The materials were tested in benzylation, alkylation and isomerization reactions and showed high activity and selectivity due to their high surface area and acidity. Pore size effects on catalytic performance were also investigated.