Hydrotalcite nanoparticles were synthesized by co-precipitation of aqueous Mg(NO(3))(2)center dot 6H(2)O and Al(NO(3))(3)center dot 9H(2)O in the presence of urea and subsequent microwave-hydrothermal treatment. The nanoparticles were activated with saturated aqueous Ca(OH)(2), and used to hydrolyze cellulose. A maximum hydrolysis yield of 47.4% with high glucose selectivity (85.8%) was achieved at 423 K. The nanocatalyst was stable and leached little as confirmed by ICP, XRD, and neutral effluent aqueous solution after reactions. It can be concluded that hydrotalcite nanoparticles activated with Ca(OH)(2) were a highly active, selective and stable catalyst for hydrolysis. (C) 2011 Elsevier Ltd. All rights reserved.