| 曹小华.化学通报,2016,79(6):528-533. |
| Y2P2W18O62?nH2O/4A-分子筛的研制及其催化合成乙酰水杨酸 |
| Preparation of Y2P2W18O62?nH2O/4A zeolite and its Catalytic Synthesis of Acetylsalicylic acid |
| 投稿时间：2015-11-05 修订日期：2015-12-17 |
| DOI： |
| 中文关键词: 4A-分子筛 磷钨酸钇 Dawson结构 乙酰水杨酸 酸中心 |
| 英文关键词:4A zeolite Yttriumphosphotungstates Dawson structure Acetylsalicylic acid Acid sites |
| 基金项目:国家自然科学(21161009)、江西省教育厅科技项目(GJJ14731, GJJ12616)及九江学院科技项目(2013KJ005)资助。 |
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| 中文摘要: |
| 以4A-分子筛为载体，Dawson结构磷钨酸钇（Y2P2W18O62?nH2O）为活性组分，采用浸渍法制备出负载型40% Y2P2W18O62?nH2O/4A-分子筛，并通过FT-IR、EDS、SEM、NH3-TPD及N2吸附-脱附等方法对催化剂进行表征。将其用于催化水杨酸和乙酸酐反应制备乙酰水杨酸，考察了各因素对反应的影响。结果表明：负载前后磷钨酸钇均保持Dawson结构，Y2P2W18O62?nH2O和40% Y2P2W18O62?nH2O/4A-分子筛均呈球形，负载后催化剂的比表面积增大，酸强度和酸量均明显提高。在优化反应条件下，即水杨酸与乙酸酐摩尔比为1:3，反应时间为30min，催化剂用量为反应物质量分数的2.3%，乙酰水杨酸收率为95.2%。催化剂重复使用6次，乙酰水杨酸收率仍保持为77.9%。 |
| 英文摘要: |
| A series of dawson type yttriumphosphotungstates supported on 4A zeolite（Y2P2W18O62?nH2O/4A zeolite）were prepared by immersion process and were used in the synthesis of acetylsalicylic acid. Catalysts were characterized by FT-IR, SEM, EDS, NH3-TPD and N2 adsorption-desorption. Influences of catalyst dosage, the mole ratio of reactants, reaction temperature, reaction time and reusability of catalyst on the reaction were investigated. The results showed that the self-prepared yttriumphosphotungstates kept Dawson structure before or after loading on 4A zeolite. Both Y2P2W18O62?nH2O and 40%Y2P2W18O62?nH2O/4A zeolite took the form of spheres. The specific surface area, acid strength and acid amount were enhanced by loading Y2P2W18O62?nH2O on 4A zeolite. The optimal conditions were as follows: w (Y2P2W18O62?nH2O/4A zeolite）2.3%, the molar ratio of salicylic acid to acetic anhydride was 1:3，reaction temperature of 80℃, reaction time of 30 min. The yield of acetylsalicylic acid could reach 95.2% under the optimum conditions and kept 77.9% after the catalyst being used six times. |
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