High quality nanosize Al-HMS was successfully synthesized using ethanol as the co-solvent. Pd atoms could be highly dispersed on this nanosize support with ordered size of ca.12 nm. TEM studies revealed that support size could influence Pd dispersion behaviors greatly. Besides, frame Al of support also played some positive role on the catalytic activity of Pd-loaded catalyst. The complete conversion of benzene could be got at 200 degrees C on this nanosize Pd/Al-HMS catalyst loaded only 0.9 wt% Pd under high gas hourly space velocity of ca.100 000 h(-1). (C) 2010 Elsevier B.V. All rights reserved.