Mesoporous transition alumina with uniform pore structure synthesized by alumisol spray pyrolysis

Liu, Chang; Ma, Qingxia; He, Hong

doi:10.1016/j.cej.2010.07.046

Cited by 35 publications

(26 citation statements)

References 45 publications

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“…The high surface area mesoporous aluminas are commonly achieved through the use of structure driving agents (SDA) such as pluronic block copolymers, ionic surfactants, fatty acids, and long chain amines [46][47][48][49][50] . Recently, the use of glucose was considered to replace SDAs 39 .…”

Section: Nitrogen Physisorptionmentioning

confidence: 99%

A Novel Synthesis Route of Mesoporous γ-Alumina from Polyoxohydroxide Aluminum

et al. 2018

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Mesoporous gamma-aluminas (γ-Al 2 O 3 ) were synthesized starting from an unusual precursor of polyoxohydroxide aluminum (POHA). This precursor was obtained from aluminum oxidation in alkaline water-ethanol solvent in the presence of d-glucose that induces the formation of a gel, which leads to the POAH powder after ethanolic treatment. Precipitated POHAs were calcined at different temperatures (300, 400, 700 and 900 °C) resulting in the metastable γ-Al 2 O 3 phase. Whereas at 300 °C no γ-Al 2 O 3 phase was formed, unexpectedly, mesoporous γ-Al 2 O 3 was obtained at 400 ºC having a high specific surface area (282 m 2 /g) and a narrow pore size distribution. At higher temperatures, the aluminas had the expected decrease in surface area: 166 m 2 /g (700 °C) and 129 m 2 /g (900 °C), respectively. The structural change from POHA to alumina calcined at 400 ºC occurs directly without the need to isolate the hydroxide or oxyhydroxide aluminum precursors. Both POHA and transition aluminas were characterized by Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), N 2 sorption and Scanning Electron Microscopy (SEM). These findings show an alternative route to produce high standard aluminas.

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Section: Nitrogen Physisorptionmentioning

confidence: 99%

A Novel Synthesis Route of Mesoporous γ-Alumina from Polyoxohydroxide Aluminum

et al. 2018

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“…Alumina seed particles were produced on-line via a spray pyrolysis setup, which has been described in detail elsewhere [33]. Liquid alumisol (AlOOH, Lot No.…”

Section: 1mentioning

confidence: 99%

Secondary aerosol formation and oxidation capacity in photooxidation in the presence of Al2O3 seed particles and SO2

et al. 2015

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To investigate the sensitivity of secondary aerosol formation and oxidation capacity to NO x in homogeneous and heterogeneous reactions, a series of irradiated toluene/NO x /air and -pinene/NO x /air experiments were conducted in smog chambers in the absence or presence of Al 2 O 3 seed particles. Various concentrations of NO x and volatile organic compounds (VOCs) were designed to simulate secondary aerosol formation under different scenarios for NO x . Under "VOC-limited" conditions, the increasing NO x concentration suppressed secondary aerosol formation, while the increasing toluene concentration not only contributed to the increase in secondary aerosol formation, but also led to the elevated oxidation degree for the organic aerosol. Sulfate formation was suppressed with the increasing NO x due to a decreased oxidation capacity of the photooxidation system. Secondary organic aerosol (SOA) formation also decreased with the presence of high concentration of NO x , because organo-peroxy radicals (RO 2 ) react with NO x instead of with peroxy radicals (RO 2 or HO 2 ), resulting in the formation of volatile organic products. The increasing concentration of NO x enhanced the formation of sulfate, nitrate and SOA under "NO x -limited" conditions, in which the heterogeneous reactions played an important role. In the presence of Al 2 O 3 seed particles, a synergetic promoting effect of mineral dust and NO x on secondary aerosol formation in heterogeneous reactions was observed in the photooxidation. This synergetic effect strengthened the positive relationship between NO x and secondary aerosol formation under "NO x -limited" conditions but weakened or even overturned the negative relationship between NO x and secondary aerosol formation under "VOC-limited" conditions. Sensitivity of secondary aerosol formation to NO x seemed different in homogeneous and heterogeneous reactions, and should be both taken into account in the sensitivity study. The sensitivity of secondary aerosol formation to NO x was further investigated under "winter-like" and NH 3 -rich conditions. No obvious difference for the sensitivity of secondary aerosol formation except nitrate to NO x was observed. secondary aerosol, oxidation capacity, synergetic promoting effect, Al 2 O 3 seed particles, sensitivity

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“…Besides, the surface area and pore structure also play important roles in the catalytic activity. The nanocrystalline Al 2 O 3 has been generally synthesized by the sol-gel 16 , precipitation 17 , flame spray pyrolysis 18 and solvothermal 13 15 methods. The solvothermal synthesis attracts the most attention because this application gives products with small uniform morphology, homogeneous chemical composition, and narrow size distribution 19 .…”

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confidence: 99%