Journal of Colloid and Interface Science, Vol.361, No.1, 25-32, 2011
Mesoporous zirconosilicate doughnuts with high performance in liquid oxidative dehydrogenation of hydroquinone to quinone
Unusual partially crystalline ordered mesoporous zirconosilicate doughnuts with Si/Zr ratio as low as 1.5 were synthesized from the aqueous polymerisation of a single source molecular precursor Zr[OSi(Ot-BuO)(3)](4) without the use of any templating agent. A radial homogenous mesoporosity (4 nm) was observed inside these very regular sub-micrometric (600 nm) doughnuts. These structures were partially crystallized in hydrothermal conditions (100 degrees C) into an analogous zircon (ZrSiO4) framework. The formation mechanism has been investigated. It is evidenced that chlorine anions Cl- concentration and pH value are essential to achieve the process, even if their role is still a matter of investigations. The obtained materials demonstrated even higher catalytic activity, selectivity and stability in the liquid oxidative dehydrogenation of hydroquinone to 1,4-benzoquinone compared to TS-1 zeolite catalysts and amorphous highly ordered mesoporous zirconosilicate materials. (C) 2011 Elsevier Inc. All rights reserved.
Keywords:Zirconosilicate;Mesoporous;Single molecular source;Partially crystalline;Doughnut shape morphology;Oxidative dehydrogenation