The Synthesis And Preliminary Study On Mechanism Of Mesoporous Zro₂

Mesoporous size, regular pore structure and good surface cohesion characteristics of mesoporous ZrO₂ are more effective for various types of catalytic reaction (such as the oxidation and acid catalyst) and adsorption. And mesoporous ZrO₂ also shows excellent catalytic properties in dehydration, hydrogenation and hydrogen exchange reaction. The synthetic process of mesoporous ZrO₂ is affected by a wide range of impact and its synthetic mechanism is complicated. Therefore, exploring the synthetic methods and optimizing the synthetic conditions of mesoporous ZrO₂ still have practical significance. In this article, mesoporous ZrO₂ was synthesized with inexpensive industrial ZrOCl2·8H2O, SBS, C₆H₁₂O₆ and C₁₂H₂₂O₁₁, PVP. This work discussed the influence of the reaction conditions for the pore structure. Furthermore, preliminary study on synthetic mechanism of mesoporous ZrO₂ was investigated.The main contents are shown as follows:First, the article reviewed the mechanism research of mesoporous materials, and emphasised on research progress of mesoporous ZrO₂ and the main problems of current preparation of mesoporous ZrO₂.Second, mesoporous ZrO₂ was synthesized by hydrothermal method, deposition method and microwave method with SDS. It is found that: 1) The precursors with lamellar mesoporous structure were synthesized by three methods. It was indicated that the SDS indeed play a structural role of guidance in synthesized mesoporous structure. 2) The precursor was dealed with the best way of NaOH solution. The relatively orderly mesoporous structure can be maintained to 500 degrees centigrade. 3) The sample synthesized by hydrothermal method has the most orderly after removing template. The main reason was that the precursors were synthesized with semi-crystalline structure.Third, the mesoporous ZrO₂ was synthesized by deposition method with C₆H₁₂O₆ and C₁₂H₂₂O₁₁. The influences of the different synthetic conditions on the pore structure of product were surveyed. The optimum reaction conditions were determined and more orderly mesoporous ZrO₂ was prepared. We found that the products prepared with the two sugar molecules had similar mesoporous structure. It is possible that the hydrolysate glucose and fructose of C₁₂H₂₂O₁₁ play a role in the real template.Forth, the mesoporous ZrO₂ was synthesized by deposition method with PVP. The mesoporous ZrO₂ was prepared with different synthetic conditions. We found that products all had a significant hysteresis in adsorption isotherm. Further, the shape of hysteresis loop and the type of isotherm have changed with the different preparation conditions. Therefore, the surface area and pore structure of sample was regulated by changing the preparation conditions.