New facile way to isomorphously substituted Cr-β zeolite and its catalytic performance

A new facile way was reported to incorporate high amount of chromium ions into the framework of BEA by a directly static hydrothermal route through the co-hydrolysis of TEOS with metal ions in acidic media. Various synthesis parameters including the co-hydrolysis route, Cr2O3/SiO2, alkalinity, and crystallization time were investigated to obtain the suitable conditions. The synthesized samples were characterized by IR, ICP, UV-vis and SEM. The results showed that the metal ions were incorporated into the crystal lattice of BEA. The catalytic performance was assessed in the oxidation of benzyl alcohol reaction, and the framework Cr demonstrated superior activity than impregnated Cr2O3 particles. Meanwhile, the recycling test of Cr-substituted beta zeolite was studied for the first time, and the good catalytic stability gave a further proof of incorporation of Cr into zeolite framework. (C) 2012 Elsevier Inc. All rights reserved.