Novel Metal Dissolution Approach for The Synthesis of Mesoporous, Multi-valent Metal Oxide Based Materials and Green, Heterogeneous Catalytic Activities and Excellent Adsorption Properties

Authors

Wimalika Rasangi Kumari Thalgaspitiya, University of Connecticut - StorrsFollow

Date of Completion

12-2-2019

Embargo Period

12-1-2022

Keywords

Mesoporous Materials, Metal Oxides, Heterogeneous Catalysis, Composites, Graphene Oxide, Multi-valent, Metal dissolution, Green, Inorganic Chemistry, Materials Science

Major Advisor

Prof. Steven L. Suib

Associate Advisor

Dr. Alfredo Angeles-Boza

Associate Advisor

Dr. Gael Ung

Associate Advisor

Dr. Jose Gascon

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 catalytic activities on mesoporous metal oxide-based materials are reported. A novel metal dissolution approach is introduced to synthesize a series of mesoporous metal oxides which includes s block, p block, transition metal, and post-transition metal oxides. The materials show excellent liquid phase heterogeneous catalytic activities, dye adsorption, and photocatalytic dye degradation under green reaction conditions. Green, highly efficient sp²-sp³ C-C coupling by mesoporous molybdenum oxide and catalytic oxidation of organosulfur compounds by mesoporous tungsten oxide are reported. Furthermore, the syntheses and characterization of novel molybdenum tungsten mixed oxide (Mo_0.5W_0.5O₃) and a series of high surface area metal titanates (where the metal = Bi, Mg, V, Mn, Fe, Co, Ni, Cu, Zn, Mo, W, and Ce) are reported. Highly efficient catalytic sp³-sp² C-C coupling reactions are conducted with mesoporous molybdenum tungsten mixed oxide. Furthermore, green catalytic oxidation of aniline to nitrosobenzene is conducted using mesoporous W/Ti binary metal oxide. A series of transition metal-doped titanium dioxide- reduced graphene oxide composites is synthesized by doping TiO₂ with different transition metals (Mn, Co, Ni, Mo, and W) followed by anchoring the nano-particles on reduced graphene oxide (rGO) sheets. The catalytic acetal formation and excellent dye adsorption and photocatalytic dye degradation properties of the composites are studied. The synthesized materials are comprehensively characterized using PXRD, in-situ PXRD, Raman, FT-IR, SEM, EDX, TEM, XPS, TGA, BET, and UV-visible spectroscopy. The products obtained from heterogeneous catalysis are analyzed using GCMS, ¹H, and ¹³C NMR spectroscopic techniques.

Recommended Citation

Thalgaspitiya, Wimalika Rasangi Kumari, "Novel Metal Dissolution Approach for The Synthesis of Mesoporous, Multi-valent Metal Oxide Based Materials and Green, Heterogeneous Catalytic Activities and Excellent Adsorption Properties" (2019). Doctoral Dissertations. 2359.
https://digitalcommons.lib.uconn.edu/dissertations/2359