The Preparation Of Rare Earth Oxides With Nano Ordered Structure By Sol-Gel Method

Nano rare earth catalysis materials are widely applied because of their solid-catalysis function. We can prepare nano ordered structure rare earth oxides, which could has a breakthrough in specific surface area, thermal stability and ordered structure of catalysis materials, then build up an base for highly effective catalysis materials'preparation and application. In this paper by a sol-gel template method, using industrialized reagent poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block coplymer P123 as template, ZrOCl₂ and rare earth chloride(CeCl₃·7H₂O,LaCl₃·7H₂O,NdCl₃·6H₂O)as raw materials, we had synthesized a series of nano ordered structure CeO₂,ZrO₂ and Ce_xZr_1-xO₂,La_xZr_1-xO₂,Nd_xZr_1-xO₂ solid solutions. The influence of all kinds of parameters (the additive amount of acac, the additive amount of urea, the aging time, the stirring temperature, the the crystallizing temperature and calcining temperature, etc) and different Re/Zr to samples'specific surface area,crystal structure, pore order and thermal stability in the process of synthesis were studied , and the functional principal were analyzed too. By means of XRD, BET, BJH, TEM and EDS, we had tested the samples. The experiments indicated that by the natural aging way, when pH=1 and ethanol concentration was high, we can synthesized nano structure CeO₂ crystal which specific surface area was 76m²/g after calcining at 400℃. However, the samples'pore distribution was wide and order was bad. Then altering the preparing method, when not adding Acac, adding 0.02mol urea, aging 48h in 80℃, crystallizing 48h in 120℃, we had synthesized ZrO₂ mesoporous materials by the method of template self-assembly technology, which specific surface area was 156m²/g, pore distribution was narrow and order was good. By the same method, we had synthesized nano ordered structure CeO₂ mesoporous materials which specific...