This study examines the catalytic performance of SDS (sodium dodecyl sulfate)-modified Nb2O5/Al2O3 heterojunctions (oxide-oxide interfaces rather than semiconductor junctions) for glycerol dehydration. Utilizing alpha-Al2O3 as a seed substrate, Nb2O5 shells were synthesized through a microwave-assisted hydrothermal process. Comprehensive characterization techniques, including FTIR, TG/DTA, N2adsorption/desorption isotherms, XRD, and NH3 and pyridine temperature-programmed desorption (TPD), were employed to analyze structural and chemical properties. The SDS-modified catalysts exhibited a marked enhancement in surface acidity relative to pristine Nb2O5, with the surfactant promoting both a higher density and increased strength of acidic sites. The Nb2O5/Al2O3 catalysts exhibited superior glycerol conversion rates relative to the individual oxides, with Nb2O5 favoring acrolein production over acetol. This work provides valuable insights into designing efficient, acid-modified catalysts for bio-based chemical production.