Guangdong Key Laboratory of Nano-Micro Materials Research, Key Laboratory of Chemical Genomics, Shenzhen Graduate School of Peking University , Shenzhen 518055, People's Republic of China.
ACS Appl Mater Interfaces. 2014 Feb 26;6(4):2718-25. doi: 10.1021/am405202d. Epub 2014 Feb 4.
Monodisperse porous zirconia (ZrO2) microspheres with nanocrystallized framework were fabricated by impregnation of porous polymer microspheres as a novel hard template with zirconia precursors followed by calcination to remove the template. Porous phosphorylated zirconia (PhZr) microspheres were prepared by further treating porous zirconia microspheres with phosphoric acid. The morphology, structure, and properties of these microspheres were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption/desorption measurement, FT-IR, and X-ray powder diffraction. The as-prepared zirconia and phosphorylated zirconia microspheres showed uniform particle size and well-defined morphology. The phosphorylated zirconia microspheres served as highly active solid acid catalysts for Friedel-Crafts alkylation of indoles with chalcones and could be reused for 22 cycles with negligible loss of activity. In situ pyridine-adsorbed FT-IR analysis of the best performing PhZr microspheres suggested the presence of both Lewis and Brønsted acid sites, and the total acidity as measured by temperature-programmed desorption of ammonia (NH3-TPD) was 328 μmol·g(-1).
单分散多孔氧化锆（ZrO2）微球具有纳米晶化骨架，是通过浸渍多孔聚合物微球作为新型硬模板，然后用锆前驱体进行煅烧去除模板制得的。多孔磷酸化氧化锆（PhZr）微球是通过进一步用磷酸处理多孔氧化锆微球制得的。通过扫描电子显微镜（SEM）、透射电子显微镜（TEM）、N2 吸附/脱附测量、FT-IR 和 X 射线粉末衍射研究了这些微球的形态、结构和性能。所制备的氧化锆和磷酸化氧化锆微球具有均匀的粒径和明确的形态。磷酸化氧化锆微球作为高效固体酸催化剂，可用于吲哚与查尔酮的 Friedel-Crafts 烷基化反应，可重复使用 22 次，活性损失可忽略不计。最佳性能的 PhZr 微球的吡啶原位吸附 FT-IR 分析表明，存在路易斯酸和布朗斯台德酸位，用氨程序升温脱附（NH3-TPD）测定的总酸度为 328 μmol·g-1。
