The water adsorption properties of modified porous sorbents for solar thermal energy storage and heat transformation have been investigated by measurements of water adsorption isotherms, microcalorimetry and storage tests. A chabazite type SAPO, a dealuminated faujasite type zeolite, and a mesostructured aluminosilicate, have been synthesized and compared with common zeolites NaX, NaY and silica gel. It has been found that optimized lattice composition and pore architecture contribute to well adapt hydrophilic properties and a beneficial steep isotherm. (C) 2013 Elsevier Ltd. All rights reserved.