Date of Completion

6-17-2020

Embargo Period

6-17-2025

Keywords

Mesoporous materials, Heterogeneous catalysis, Metal oxides, Mixed metal oxides, Nanocomposites, Solid acid catalysts

Major Advisor

Prof. Steven L. Suib

Associate Advisor

Prof. Christian Bruckner

Associate Advisor

Prof. Jose Gascon

Associate Advisor

Dr. Alfredo Angeles-Boza

Associate Advisor

Dr. Fatma Selampinar

Field of Study

Chemistry

Degree

Doctor of Philosophy

Open Access

Campus Access

Abstract

Research conducted on the synthesis, characterization, and the application of mesoporous metal oxides and nanocomposites is reported. Surfactant assisted sol-gel based inverse micelle methods are used for the catalyst synthesis. The synthesized oxides are comprehensively characterized using PXRD, BET, SEM, TEM, Raman, XPS, TGA, XRF, and UV-Vis, and TPD. All the materials act as efficient catalysts in various heterogeneous reactions. GC-MS, and 1H-NMR spectroscopic techniques are used to identify and quantify the products obtained from the catalytic reactions. Substrate scope, reusability tests, leaching tests, and kinetic studies are performed for all the developed catalytic protocols.

Chapter 2 discusses the synthesis of Tin molybdenum mixed metal oxide having a high surface area (243 m2/g). A metal dissolution reverse micelle method is used as the synthesis method. This material is used as a solid acid catalyst for the tandem synthesis of imines from direct coupling of amines and alcohols. All the reactions are carried out at room temperature under solvent free conditions. A wide scope of substrates is converted to their corresponding imines in 20 minutes. Therefore, the catalyst shows very high turnover frequencies. The only byproduct formed during

the reaction is water. Hence, this protocol is an environmentally benign, green approach for making symmetric and asymmetric imines.

Chapter 3 focuses on the synthesis of mesoporous crystalline niobium oxide. The synthesized material shows higher surface areas, tunable pore sizes, and a uniform pore size distribution. This niobium oxide is an excellent solid acid for the catalysis of alkyne hydration. The Brönsted acid sites present in the material are responsible for the high catalytic activity.

Chapter 4 discusses the development of mesoporous Ni/NiO nanocomposite. Partial reduction of NiO is performed to obtain Ni/NiO composite while retaining the mesoporosity. Due to the presence of both Ni and NiO, this material acts as an excellent catalyst for Csp2-Csp3 cross coupling reactions. The mechanism of the catalytic reaction is investigated by computational (Ab initio) methods.

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Available for download on Tuesday, June 17, 2025

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