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Targeted Synthesis and Characterization of Nanostructured Silicate Building Block Supports and Heterogeneous Catalysts with Tungsten(VI) Or Zirconium(IV) Centers

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Targeted Synthesis and Characterization of Nanostructured Silicate Building Block Supports and Heterogeneous Catalysts with Tungsten(VI) Or Zirconium(IV) Centers University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 12-2011 Targeted Synthesis and Characterization of Nanostructured Silicate Building Block Supports and Heterogeneous Catalysts with Tungsten(VI) or Zirconium(IV) Centers Michael Edward Peretich [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Inorganic Chemistry Commons Recommended Citation Peretich, Michael Edward, "Targeted Synthesis and Characterization of Nanostructured Silicate Building Block Supports and Heterogeneous Catalysts with Tungsten(VI) or Zirconium(IV) Centers. " PhD diss., University of Tennessee, 2011. https://trace.tennessee.edu/utk_graddiss/1215 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Michael Edward Peretich entitled "Targeted Synthesis and Characterization of Nanostructured Silicate Building Block Supports and Heterogeneous Catalysts with Tungsten(VI) or Zirconium(IV) Centers." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Doctor of Philosophy, with a major in Chemistry. Craig Barnes, Major Professor We have read this dissertation and recommend its acceptance: Charles Feigerle, George Schweitzer, Madhu Dhar Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Targeted Synthesis and Characterization of Nanostructured Silicate Building Block Supports and Heterogeneous Catalysts with Tungsten(VI) or Zirconium(IV) Centers A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville Michael Edward Peretich December 2011 Copyright © 2011 by Michael E Peretich All rights reserved. ii DEDICATION This dissertation is dedicated to everyone who has supported me over the years especially my wife Amanda Peretich my parents and in-laws Ed and Irene Peretich J.B. and Jill Anderson my siblings Melissa and Austin Vigil Mark Peretich Jamie and Dina Anderson Brian Anderson iii ACKNOWLEDGEMENTS This dissertation would not have been possible without the assistance of many individuals. I truly feel that words cannot describe how much I appreciate everyone who has supported me over the years. I will do my best to acknowledge those individuals who I feel played an important role in helping me complete this dissertation. First, I would like to thank my research adviser, Dr. Craig Barnes, for supporting and encouraging me over the years. He helped make me the chemist I am today and I absolutely feel one of the best decisions I made in graduate school was to join his research lab. I would also like to thank my committee members, Dr. Charles Feigerle, Dr. George Schweitzer, and Dr. Madhu Dhar for agreeing to commit time and effort to serve on my committee. I would also like to thank the entire Chemistry Department staff, especially members of the Business Office (Beverly Adams, Gail Cox, Darrell Lay, Sharon Marshall), the Electronics Shop (Bill Gurley, Johnny Jones, Jim Murphy, Gary Wynn), the Machine Shop (Tim Free, Gene French, Eddie Wilson), the Main Office (Jill Bodenheimer, Lisa Bonds, Elizabeth Miller), and the Glassblowing Shop (Art Pratt). These individuals provide vital support for the Chemistry Department and each of them deserves acknowledgement and thanks for all of the work that they do. I would not have been able to complete this dissertation without the assistance of each of the individuals mentioned above. I gratefully acknowledge the motivation and support of current and former group members: Josh Abbott, Nan Chen, James Humble, Austin Albert, Dan Taylor, Dr. Richard Mayes, Dr. Ming-Yung Lee, Dr. Geoff Eldridge, Katherine Sharp, Justin Roop, Dr. Jiri Pinkas, Ales Styskalik, and Dustin Collier. I appreciate the helpful discussions about research, the long days and nights at Brookhaven, and generally making the research lab a fun place. I would especially like to acknowledge Geoff who helped me obtained a job. Josh, Nan, James, Austin, and Katherine made the lab such an enjoyable place that I can honestly say I was excited to go to work each day. I could always count on Austin and James to keep everyone in the lab on their toes because you never knew what either one of them would get into. I would also like to thank several JMU faculty members who started my development as a professional chemist and who have supported Amanda and I throughout the years. I would like iv to thank Dr. Tom DeVore (my undergraduate research advisor), Dr. Donna Amenta, Dr. John Gilje, Dr. Barbara Reisner, Dr. Kevin Caran, and Dr. David Brakke. Last, but certainly not least, I would like to acknowledge my family and friends for their love and support. My family, especially my parents (Ed and Irene), has been tremendously supportive and loving. Mark and Melissa set the bar high and always pushed me to do my best. I know I would not have finished this dissertation without the love and support of my wonderful wife, Amanda. She has suffered through the difficult times and sacrificed so much in order for me to complete my graduate studies and pursue a career as a Ph.D. chemist. She has been and will always be there for me as will I for her through good times and bad. v ABSTRACT Catalysts play a vital role in almost every aspect of our lives and are used in the production of fuels, polymers, chemicals, foods, and pharmaceuticals. One challenge facing the heterogeneous catalysis community is the targeted synthesis of dispersed catalyst ensembles. The Barnes research group has developed a general methodology for the synthesis of nanostructured silicate building block supports and heterogeneous catalysts. This methodology provides researchers with the ability to control the dispersion of surface functionality, the dispersion of metal cation centers, the number of linkages from the metal cation center to the support, the surface area of the support, and the porosity of the support. This dissertation describes work aimed at synthesizing and characterizing nanostructured silicate building block supports and heterogeneous catalysts. Nanostructured silicate building block supports were synthesized by reacting SiCl4py2 with Si8O12(OSnMe3)8. The resulting supports contained spatially isolated Me3Sn groups and the density of Me3Sn groups was targeted by varying the stoichiometric ratio of reactants. The stoichiometric ratio of reactants also controlled the surface area and porosity of the supports. Nanostructured heterogeneous catalysts with isolated tungsten(VI) or zirconium(IV) centers were synthesized by reacting a limiting amount of a metal chloride with either Si8O12(OSnMe3)8 or a premade silicate building block support. Two types of catalysts ensembles were targeted: embedded and surface. Embedded ensembles were successfully targeted using WOCl4 and ZrCl4 while the reaction between WCl6 and the building block did not result in the preparation of the targeted ensemble. However the resulting ensemble was thoroughly characterized even though the targeted ensemble was not produced. In all three cases a single type of catalyst ensembles was synthesized and a high surface area silicate support was generated around the embedded ensembles without disrupting the ensemble itself. Surface ensembles were successfully targeted using ZrCl4. The reaction between the tungsten chlorides (WOCl4 and WCl6) and the premade support did not result in the preparation of the targeted ensembles however the resulting ensembles were thoroughly characterized. vi TABLE OF CONTENTS Chapter 1. Introduction................................................................................................................1 Importance of Catalysis .............................................................................................................. 1 What is a Catalyst?.................................................................................................................. 1 Types of Catalysts............................................................................................................... 4 Homogeneous versus Heterogeneous Catalysts...................................................................... 4 The Active Site and the Catalyst Ensemble............................................................................ 5 The Surface Functionality of a Support.................................................................................. 8 The Porosity of a Support ..................................................................................................... 10 Traditional Synthetic Methodologies........................................................................................ 10 Supports and Heterogeneous Catalysts with Embedded Active Sites .................................. 12 Sol-Gel Process................................................................................................................. 12 Summary of Sol-Gel Process........................................................................................ 14 Templating
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