氧化锆层柱磷酸锆的制备及性能

考察了不同制备因素对形成氧化锆层柱磷酸锆的影响,发现适中的锆离子浓度,较低的反应温度及较长的反应时间有利于形成稳定的氧化锆层柱磷酸锆。样品经250℃焙烧后形成较为规整的层柱结构,氧化锆柱与层板间以P-O-Zr键相连,比表面为107～183m^2/g,孔径较集中地为2.5nm。层柱样品表面只存在L酸位,无B酸位。对异丙醇脱水反应和苯甲醛还原反应有较好的反应活性,其比活性优于纯的氧化锆,表明它具有良好的酸催化和酸碱双功能催化作用。

Preparation and characterization of ZrO~2-pillared zirconium phosphate

Different factors in the preparation of ZrO~2-pillared zirconium phosphate were explored systematically. An appropriate concentration of Zr^4^+, a lower reaction temperature, and a longer reaction time facilitate the formation of stable ZrO~2-pillared zirconium phosphates. A pillared structure with surface area of 107～183m^2/g and pore size of 2.5nm was obtained after calcination at 250℃. The ZrO~2 pillars and the zirconium phosphate sheets were linked through P-O-Zr bonding. IR pyridine-adsorption studies indicate that surface acid sites of the pillared samples are mainly Lewis acid sites. These pillared materials showed good activities in dehydration of isopropanol and reduction of benzaldehyde. Owing to the large surface area and good mesoporosity, their specific activities in the reactions are higher than those of pure ZrO~2, implying that they are new hopeful materials for preparing acid catalysts or acid-base bifunctional catalysts.