Preparation of monolithic SiO2-Al2O3 cryogels with inter-connected macropores through ice templating

Hirotomo Nishihara, Shin R. Mukai, Yusuke Fujii, Teruoki Tago, Takao Masuda, Hajime Tamon

    Research output: Contribution to journalArticlepeer-review

    51 Citations (Scopus)

    Abstract

    Macroporous monoliths of SiO2-Al2O3 cryogels were prepared. Macropores were generated by using ice crystals as the template, while the walls which surround the macropores were tailored as porous cryogels by freeze drying. Macropores and walls formed honeycomb-like structures, which were confirmed from scanning electron microscopy images of cross-sections of the samples. It was confirmed that the sizes of the macropores and the wall thicknesses were respectively in the ranges of 10-20 m and 200-500 nm. Al mapping analysis by energy dispersive X-ray diffractometry showed that Al atoms were homogeneously dispersed throughout the samples without local aggregation. Moreover, Raman spectroscopy and 27Al NMR spectroscopy indicated that Al atoms were incorporated into the silica framework by forming an Al-O-Si polymeric network. Nitrogen adsorption-desorption measurements indicated that the walls were micro/mesoporous with high BET surface areas (>700 m2 g-1) and large pore volumes (>0.45 cm 3 g-1). Moreover, NH3-TPD measurements revealed that the samples had acid sites, which allowed this material to be used as a solid acid catalyst.

    Original languageEnglish
    Pages (from-to)3231-3236
    Number of pages6
    JournalJournal of Materials Chemistry
    Volume16
    Issue number31
    DOIs
    Publication statusPublished - 2006 Aug 11

    ASJC Scopus subject areas

    • Chemistry(all)
    • Materials Chemistry

    Fingerprint

    Dive into the research topics of 'Preparation of monolithic SiO2-Al2O3 cryogels with inter-connected macropores through ice templating'. Together they form a unique fingerprint.

    Cite this