TY - JOUR

T1 - Mesoporous aerogel-like Al-Si oxides obtained via supercritical antisolvent precipitation of alumina and silica sols

AU - Nesterov, Nikolai S.

AU - Shalygin, Anton S.

AU - Pakharukova, Vera P.

AU - Glazneva, Tatyana S.

AU - Martyanov, Oleg N.

N1 - Publisher Copyright: © 2019 Elsevier B.V.

PY - 2019/7/1

Y1 - 2019/7/1

N2 - A method of alumina and silica sols precipitation in supercritical CO 2 has been developed for the first time to prepare alumina and silica doped alumina. The silicon content of samples is varied within the range from 0 to 30 mol. %. The approach suggested can be considered as a development of supercritical antisolvent (SAS) method that is widely used to prepare powders from solutions but not sols. The alumina and silicon-doped alumina obtained are shown to be mesoporous materials with narrow size distribution in the range of 3–5 nm. The high-temperature treatment of the sample containing 10 mol. % of Si results in the formation of γ-Al 2 O 3 phase followed by its transition into the δ-Al 2 O 3 phase at 1200 °C without α-Al 2 O 3 phase formation. It is demonstrated that the gradual introduction of silica into the alumina allows one to fine-tune the strength and amount of acid sites existing in oxides.

AB - A method of alumina and silica sols precipitation in supercritical CO 2 has been developed for the first time to prepare alumina and silica doped alumina. The silicon content of samples is varied within the range from 0 to 30 mol. %. The approach suggested can be considered as a development of supercritical antisolvent (SAS) method that is widely used to prepare powders from solutions but not sols. The alumina and silicon-doped alumina obtained are shown to be mesoporous materials with narrow size distribution in the range of 3–5 nm. The high-temperature treatment of the sample containing 10 mol. % of Si results in the formation of γ-Al 2 O 3 phase followed by its transition into the δ-Al 2 O 3 phase at 1200 °C without α-Al 2 O 3 phase formation. It is demonstrated that the gradual introduction of silica into the alumina allows one to fine-tune the strength and amount of acid sites existing in oxides.

KW - Acidity

KW - Alumina-silica

KW - Mesoporous alumina

KW - SAS

KW - Sols

KW - Supercritical antisolvent

KW - FLUIDS

KW - CO2

KW - NANO-PARTICLES

KW - BASICITY

KW - NANOPARTICLES

KW - HYDROGEN

KW - GEORGEITE

KW - FISCHER-TROPSCH CATALYSTS

KW - SURFACE

KW - ACIDITY

UR - http://www.scopus.com/inward/record.url?scp=85064166327&partnerID=8YFLogxK

U2 - 10.1016/j.supflu.2019.03.014

DO - 10.1016/j.supflu.2019.03.014

M3 - Article

AN - SCOPUS:85064166327

VL - 149

SP - 110

EP - 119

JO - Journal of Supercritical Fluids

JF - Journal of Supercritical Fluids

SN - 0896-8446

ER -