Microporous Glass‐Ceramics in NASICON‐Type Copper(II) Titanium Phosphate

Abstract

A novel porous glass‐ceramic with a skeleton of a NASICON‐type copper(II) titanium phosphate was prepared via the controlled crystallization of a glass and the subsequent chemical leaching of the resulting dense glass‐ceramic. A volume‐crystallized dense glass‐ceramic comprised of CuTi 2 (PO 4 ) 3 and Cu 3 (PO 4 ) 2 , whose surface was covered by a thin layer of CuO, was prepared by reheating a glass with a nominal composition of 50CuO20TiO 2 30P 2 O 5 (in mol%) in air. When the resulting glass‐ceramic was leached with dilute HCl, the Cu 3 (PO 4 ) 2 and CuO phases were dissolved out selectively, and a cuprous NASICON crystal of CuTi 2 (PO 4 ) 3 was converted to its cupric type, CuTi 4 (PO 4 ) 6 , which was left as a skeleton of the porous materials. The specific surface area and the average pore radius of the porous glass‐ceramic obtained were ∼70 m 2 /g and ∼7 nm, respectively. The porous glass‐ceramic showed high catalytic activities for the dehydration of 2‐propanol.