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Sulfonic Acid Catalysts Based on Porous Carbons and Polymers Tian Xiao Ning

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Sulfonic Acid Catalysts Based on Porous Carbons and Polymers Tian Xiao Ning SULFONIC ACID CATALYSTS BASED ON POROUS CARBONS AND POLYMERS TIAN XIAO NING NATIONAL UNIVERSITY OF SINGAPORE 2009 SULFONIC ACID CATALYSTS BASED ON POROUS CARBONS AND POLYMERS TIAN XIAO NING (M.Eng) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF CHEMICAL AND BIOMOLECULAR ENGINEERING NATIONAL UNIVERSITY OF SINGAPORE 2009 Acknowledgement Acknowledgement I would like to convey my deepest appreciation to my supervisor, Assoc. Prof. Zhao X. S., George for his constant encouragement, invaluable guidance, patience and understanding throughout the whole period of my PhD candidature. This project had been a tough but enriching experience for me in research. I would like to express my heartfelt thanks to Assoc. Prof. Zhao for his guidance on writing scientific papers including this PhD thesis. In addition, I want to express my sincerest appreciation to the Department of Chemical and Biomolecular Engineering for offering me the chance to study at NUS with a scholarship. It’s my pleasure to work with a group of brilliant, warmhearted and lovely people, Dr. Su Fabing, Dr. Lv Lu, Dr. Zhou Jinkai, Dr. Li Gang, Dr. Wang Likui, Dr. Bai Peng, Ms. Lee Fang Yin, Ms. Liu Jiajia, Ms. Zhang Li Li, Ms. Wu Pingping, Mr. Cai Zhongyu, Mr. Dou Haiqing, and Mr. Zhang Jingtao. Particular acknowledgement goes to Mr. Chia Phai Ann, Mr. Shang Zhenhua, Dr. Yuan Zeliang, Mr. Mao Ning, Dr. Rajarathnam D., Madam Chow Pek Jaslyn, Mdm Fam Hwee Koong Samantha, Ms Lee Chai Keng, Ms Tay Choon Yen, Mr. Toh Keng Chee, Mr. Chun See Chong, Ms. Ng Ai Mei, Ms. Lum Mei Peng Sharon, and Ms. How Yoke Leng Doris for their kind supports. I thank my parents. It is no exaggeration to say that I could not complete the PhD work without their generous help, boundless love, encouragement and support. i Table of Contents Table of Contents Acknowledgement ........................................................................................................... i Table of Contents ............................................................................................................ ii Summary ......................................................................................................................... v Nomenclature ................................................................................................................ vii List of Tables ............................................................................................................... viii List of Figures ................................................................................................................ ix Chapter 1. Introduction ................................................................................................... 1 1.1 Solid sulfonic acid catalysts .................................................................................. 1 1.2 Objectives of thesis work ...................................................................................... 3 1.3 Structure of thesis ................................................................................................. 4 Chapter 2. Literature Review .......................................................................................... 7 2.1 Propylsulfonic-modified mesoporous silica ......................................................... 7 2.2 Arenesulfonic-acid modified material ................................................................ 18 2.3 Perfluorosulfonic-acid modified mesopouous material ...................................... 23 2.4 Organosulfonic-modified periodic mesoporous organosilica ............................. 28 2.5 Sulfonic acid-modified carbon ............................................................................ 37 2.6 Sulfonic acid-modified resin ............................................................................... 43 Chapter 3. Experimental Section .................................................................................. 48 3.1 Reagents and apparatus ....................................................................................... 48 3.2 Preparation of sulfonic acid catalysts ................................................................. 49 ii Table of Contents 3.3 Characterization .................................................................................................. 53 3.4 Evaluation of conversion for acetic acid ............................................................. 58 Chapter 4. Sulfonated Mesoporous Carbons and Carbon-silica Composites ............... 59 4.1 Introduction ......................................................................................................... 59 4.2 Catalyst preparation ............................................................................................ 60 4.3 Characterization of sulfonated mesoporous carbons and carbon-silica composites ................................................................................................................................... 60 4.4 Catalytic properties in esterification ................................................................... 71 4.5 Summary ............................................................................................................. 73 Chapter 5. Sulfonated Mesoporous Polymer Resins and Carbons ............................... 74 5.1 Introduction ......................................................................................................... 74 5.2 Catalyst preparation ............................................................................................ 75 5.3 Characterization of sulfonated mesoporous polymers and carbons .................... 75 5.4 Catalytic properties in esterification ................................................................... 86 5.5 Summary ............................................................................................................. 88 Chapter 6. Sulfonated Polypyrrole and Carbon Nanospheres ...................................... 90 6.1 Introduction ......................................................................................................... 90 6.2 Catalyst preparation ............................................................................................ 90 6.3 Characterization of sulfonated polypyrrole and carbon nanospheres ................. 91 6.4 Catalytic properties in esterification ................................................................... 91 6.5 Summary ........................................................................................................... 104 iii Table of Contents Chapter 7. Sulfonated Polystyrene-Divinylnenzene Spheres ..................................... 105 7.1 Introduction ....................................................................................................... 105 7.2 Catalyst preparation .......................................................................................... 106 7.3 Characterization of sulfonated polystyrene spheres ......................................... 106 7.4 Catalytic properties in esterification ................................................................. 117 7.5 Summary ........................................................................................................... 118 Chapter 8. Kinetics and Mechanism of Esterification Reaction over Sulfonated Polystyrene-Divinylbenzene Spheres ......................................................................... 120 8.1 Introduction ................................................................................................. 120 8.2 Results and Discussion ............................................................................... 122 8.3 Summary ........................................................................................................... 133 Chapter 9. Conclusions and Recommendations .......................................................... 134 9.1 Conclusions ................................................................................................. 134 9.2 Recommendations ....................................................................................... 137 References ................................................................................................................... 139 Appendix: List of publications .................................................................................... 152 iv Summary Summary Liquid sulfuric acid is a widely used homogeneous catalyst in many important chemical processes. However, liquid sulfuric acid has a number of problems, such as corrosion, toxicity, and disposal problem. Therefore, solid sulfonic acid catalysts are strongly desired. Over the past few years, solid sulfonic acid materials have been investigated, aimed to replace the liquid sulfuric acid catalyst. The preparation of such solid sulfonic acid materials generally includes functionalization of porous silica, carbon and polymer materials with propylsulfonic acid, arenesulfonic acid, perfluorosulfonic acid and sulfonic acid groups. Carbon in its chemical allotropes of graphite and diamond occurs in a great variety of species and has been developed to a large number of applications as structural and functional materials. The underlying reason for this unique manifold of species is twofold: (1) the co-ordination chemistry of carbon is flexible in allowing continuous mixtures of C=C and C-C bonding in one structure. This leads to an infinite possibility of 3-dimensional structures (e.g.: carbon nanotubes, graphene, C60) and to continuous
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