Iron-substituted cubic silsesquioxane pillared clays: Synthesis, characterization and acid catalytic activity

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:510

Article

Potsi, Georgia^1,2  Ladavos, Athanasios K.³  Petrakis, Dimitrios⁴  Douvalis, Alexios P.⁵  Sanakis, Yiannis⁶  Katsiotis, Marios S.⁷  Papavassiliou, Georgios⁶  Alhassan, Saeed⁷  Gournis, Dimitrios¹  Rudolf, Petra² 

[1] Univ Ioannina, Dept Mat Sci & Engn, Ioannina 45110, Greece

[2] Univ Groningen, Zemike Inst Adv Mat, Nijenborgh 4, NL-9747 AG Groningen, Netherlands

[3] Univ Patras, Sch Nat Resources & Enterprise Management, Agrinion 30100, Greece

[4] Univ Ioannina, Dept Chem, Ioannina 45110, Greece

[5] Univ Ioannina, Phys Dept, Ioannina 45110, Greece

[6] Inst Nanosci & Nanotechnol, NCSR DEMOKRITOS, Athens 15310, Greece

[7] Petr Inst, Dept Chem Engn, POB 2533, Abu Dhabi, U Arab Emirates

关键词: Pillared clays;    Montmorillonite;    Polyhedral silsesquioxanes;    Acid activation;    Catalysis;    Isopropanol dehydration;   

DOI  :  10.1016/j.jcis.2017.09.003

来源: Elsevier

【 摘 要 】

Novel pillared structures were developed from the intercalation of iron-substituted cubic silsesquioxanes in a sodium and an acid-activated montmorillonite nanoclay and evaluated as acid catalysts. Octameric cubic oligosiloxanes were formed upon controlled hydrolytic polycondensation of the corresponding monomer (a diamino-alkoxysilane) and reacted with iron cations to form complexes that were intercalated within the layered nanoclay matrices. Upon calcination iron oxide nanoparticles are formed which are located on the silica cubes (pillars) and on the surfaces of the clay platelets. Acid activation of the nanoclay was performed in order to increase the number of acid active sites in the pristine clay and thus increase its catalytic activity. A plethora of analytical techniques including X-ray diffraction, thermal analyses, Fourier transform infrared, electron paramagnetic resonance, Raman, Mossbauer and X-ray photoelectron spectroscopies and porosimetry measurements were used in order to follow the synthesis steps and to fully characterize the final catalysts. The resulting pillared clays exhibit a high specific area and show significant acid catalytic activity that was verified using the catalytic dehydration of isopropanol as a probe reaction. (C) 2017 Elsevier Inc. All rights reserved.

【 授权许可】

Free