The first high specific surface area, pillared, layered phosphate with a narrow pore size distribution

[Al13O4(OH)24(OH2) 12]7+ has been intercalated under mild conditions into ?-tin phosphate monohydrate to give ?-Sn[Al13O 4(OH)24(OH)2)12] 0.14H(PO4)2·nH2O ('Al 13SnP'); calcination of 'Al13SnP' at 400°C gives rise to an aluminium oxide-pillared material with a BET surface area of 228 m 2 g-1 and a very narrow pore-size distribution centred at a radius of 22 Å.