and Dicarboxylic Acids and Esters

114 Pages·2016·2.19 MB·English

Catalytic Conversion of Biomass-Derived Molecules into Mono-
and Dicarboxylic Acids and Esters
by
Yuran Wang
B.S., Tsinghua University (2010)
M.S., Massachusetts Institute of Technology (2014)

Submitted to the Department of Chemical Engineering
in Partial Fulfillment of the Requirements for the Degree of
Doctor of Philosophy
at the
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
June 2016
© 2016 Massachusetts Institute of Technology. All Rights reserved.

Signature of Author ………………………………………………………………………………...
Department of Chemical Engineering
May 12, 2016

Certified by ………………………………………………………………………………………...
Yuriy Román-Leshkov
Associate Professor of Chemical Engineering
Thesis Supervisor

Accepted by ………………………………………………………………………………………...
Richard D. Braatz
Edwin R. Gilliland Professor of Chemical Engineering
Chairman, Committee for Graduate Students

Catalytic Conversion of Biomass-Derived Molecules into Mono- and
Dicarboxylic Acids and Esters
by
Yuran Wang

Submitted to the Department of Chemical Engineering
on May 12, 2016 in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy in
Chemical Engineering

ABSTRACT
Biomass can serve as a renewable alternative to the inevitably depleting fossil fuel resources and
provide feedstocks for the production of fuels and chemicals. Mono- and dicarboxylic acids and
esters are key intermediates to chemical products, especially for biodegradable polymers. This
thesis has addressed the challenges in chemocatalytic synthesis of mono- and dicarboxylic acids
and esters, including gluconic acid, succinic acid, itaconic acid and their esters, from biomass-
derived molecules.
Gold (Au) catalysts have been rarely investigated for the oxidation of glucose in the absence of a
base. These conditions are critical, however, to enable the sequential one-pot combination of
cellulose hydrolysis and glucose oxidation. The study provides insights into the deactivation of the
catalysts caused by leaching and hydrothermal sintering of Au nanoparticles, as well as by
adsorption of reaction species. We found that lowering the surface density of Au on metal oxides
decreases the sintering rate of the Au nanoparticles and hence enhances the stability and activity of
the catalyst.
Levulinate derivatives are an attractive platform for the production of renewable chemicals. We
report on the oxidation of methyl levulinate into dimethyl succinate with peroxides under mild
conditions using Brønsted and Lewis acid catalysts and focuses on the reaction selectivity control.
While the molecular structure (i.e., carbon chain length and branching around the C=O group)
and the oxidant type affect the product distribution, solvent choice has the strongest impact on
changing the location of oxygen insertion into the carbon backbone. In contrast to Brønsted acids,
for water-tolerant Lewis acidic triflate salts, the reaction selectivity is affected by the size of the
metal cation.
We have developed a novel approach to synthesize unsaturated dicarboxylic acid esters via aldol
condensation of keto esters catalyzed by Lewis acidic zeolites. Hafnium-containing BEA (Hf-
BEA) zeolites are highly active, selective and stable for the condensation of ethyl pyruvate into
itaconic acid ester analogues. Analysis of the dynamic behavior of Hf-BEA under flow conditions
and studies with Na-exchanged zeolites suggest that Hf(IV) open sites possess dual functionality
for Lewis and Brønsted acid catalysis.
Thesis Supervisor: Yuriy Román-Leshkov
Title: Associate Professor of Chemical Engineering
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Acknowledgements
I am deeply grateful for all the help and support I have received throughout my Ph.D. that have
made the work presented in this thesis possible. First of all, I would like to express my sincere
gratitude to my thesis advisor Prof. Yuriy Román-Leshkov for the opportunity to work with him.
It has been a great experience. Yuriy is always encouraging and supportive. I remembered the
time when he was in the lab showing me how to install the HPLC column, his long email
guiding me how to properly plan my research, and our conversations about career development.
He also always challenged me to start with what I have in hand instead of waiting till everything is
ready. Being one of his first students, I have seen and also really appreciated his constant efforts to
equip us with the best resources to do research.
I would also like to thank my thesis committee members: Prof. William H. Green, Prof. T.
Alan Hatton and Prof. Klavs F. Jensen. Their insightful comments and hard questions prompted
me to broaden my research from various perspectives. They also have their lab doors open to me
so that I could have access to their facility to accomplish my research. I also appreciate their
support and help in my career development.
Throughout my Ph.D., I have had the opportunity to work with many brilliant collaborators.
First, I would like to thank Dr. Krishna K. Sharma, who has set up the lab when there was
nothing, taught me how to run my very first batch reactions and catalyst synthesis and established
the foundation for the base-free glucose oxidation work. My sincere thanks go to Dr. Stijn Van
de Vyver for his contribution in my very first first-author publication. He has challenged me to
present my work and my ideas in an effective way and helped me grow as a researcher. I am
grateful to Ferdinand Vogelgsang for his assistance in the Baeyer-Villiger oxidation project. I
thank Jennifer D. Lewis, who has been extremely supportive and helpful. I also really appreciated
the inspiring discussions we had about aldol condensation.
Being one of the first members in the group, I have had the privilege to meet and work with
each individual we have had. My sincere gratitude goes to Dr. Mark Mba Wright for his
friendship; Dr. Herui Dou for sharing his ‘insights’ into research and life; Dr. Murat Kaya for
synthesizing new catalysts for me and always being peaceful; Dr. Teerawit Prasomsri (Air) for all
his help, support and patience. I also thank Dr. Mehmet Zahmakiran for setting up the lab; Dr.
Tarit Nimmanwudipong for nicely inventorying our Swagelok fittings; Dr. Anthony Crisci for his
encouragement and introducing the only beer that I would be happy to drink; Dr. David
Simakov for sharing his knowledge about building reactors; Dr. Kenta Iyoki for taking lots of
work during lab cleaning; Dr. Maria Millina for sharing her thesis as a template and being helpful
and delightful; Dr. Christ Hendon for introducing Slack to the group. Many thanks go to Dr.
William Gunther for synthesizing zeolite catalysts for us; Helen Luo for taking care of lab supplies
and being very responsible, helpful and cheerful; Sean Hunt for teaching me some interesting
math, sharing his knowledge on XPS and electrocatalysis and providing the Chinese candy and
other snack supplies; Karthik Narsimhan for helping me with using the portable MS and coming
to school from home to open the lab door for me after midnight; Manish Shetty and Karthick
Murugappan for always trying to accommodating me in their busy GCMS schedule and many fun
outside the lab; Aaron Garg for taking care of the glovebox; Eric Anderson for his creative way of
taking care of the Parr reactors; Daniel Consoli for lending me his ID to open the lab door;
Hoyoung Park for sharing his new interesting results with me; Mike Orella for bringing us
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another refrigerator for sample storage; Kim Dinh for taking on many responsibilities in the group;
Zhenshu Wang for being another person that I can talk with in Chinese in the lab; Caroline
Odermatt for her friendship; Rong Liu for many fun outside lab; Marco Wonink for bringing fun
to the lab, and many others who were great colleagues. I am so grateful to work with all the
group members in Román Group. The group atmosphere has been positive, friendly, and
collaborative. Everyone in the group has been so generous to teach me new things and so
wonderful to inspire me. I have been very fortunate to have all of you in my life, who have made
the Ph.D. experience a very enjoyable one even during the most difficult times.
I would also like to thank all my friends in the ChemE Department and at MIT for their
support and friendship. Particularly, I would like to thank Dr. Nicole Yang for being my mentor
during my first year in ChemE, Dr. Rong Yang for her constant support and mentoring
throughout my doctoral studies, Dr. Caleb Class for his help on Gaussian calculations, Dr. Monica
Sircar for her advice and support, and Shengchang Tang for helping me with auto column
separations. I would also like to acknowledge all the administrative staff in the ChemE
Department, who have made my transition into a new country smooth and have been super
helpful and supportive throughout my Ph.D. life at MIT.
Last but not least, I must express my deep gratitude to my parents for being always supportive
and giving me the courage to face all the challenges. I would also like to thank my sisters and
brother for their care and support. This completion of my thesis work would not have been
possible without them.
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Table of Contents

Abstract 3
Acknowledgements 5
Table of Contents 7
1. Intro duction 9
2. Insights into the stability of gold nanoparticles supported on metal 21
oxides for the base-free oxidation of glucose to gluconic acid
3. Acid-catalyzed oxidation of levulinate derivatives to succinates under 41
mild conditions
4. Synthesis of itaconic acid ester analogs via self-aldol condensation of 59
ethyl pyruvate catalyzed by hafnium BEA zeolites
5. Conclusions and outlook 79
Appendix 89

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Chapter 1
Introduction
1. Biomass as an alternative renewable carbon source
The heavy dependence on fossil fuel resources and the ever growing plastic waste pollution are
two grand challenges we are faced with towards a sustainable future. In the past century, the
global economy has been heavily dependent on fossil fuel resources, including oil, coal and natural
gas,1,2 which have provided the material and energy foundation for modern society. In addition to
the economy prosperity, heavy dependence on fossil fuel resources has also caused significant
problems. Fossil fuel production and consumption not only are the main sources of green-house
gases (e.g., CO and CH ) and leading contributors to climate change, but also cause significant
2 4
pollutions to air, water, and soil, which in turn impose a high cost on human health.2 The
dwindling supply of fossil fuels, the disturbing economic impacts of fossil fuel price fluctuations
and the threatening effects of climate change have stimulated increasing interests and efforts in
developing clean and sustainable alternatives. Among the renewable alternative energy resources
such as solar, wind and wave power, biomass is currently the only source that provides organic
carbon to serve as a renewable feedstock to the chemical industry. Compared to petroleum-
derived molecules, most biomass-derived molecules are highly functional. By selectively
modifying the functionality via depolymerization, hydrolysis, dehydration, deoxygenation and
oxidation, etc., these molecules can be integrated into the current petroleum industry or
converted into molecules with new functions.
In addition to alleviating the societal dependence on fossil fuel sources, biomass holds the
promise to reduce plastics pollution. Plastics are ubiquitous in modern life. Among municipal
waste in Europe and the United States (U.S.), 12-25% are plastics, only 1-2% of which are
recycled.3 The estimated amount of plastic waste entered the ocean in 2010 is 4.8 to 12.7 million
metric tons, and the prediction for 2025 is one order of magnitude higher.4 Since most of the
plastic waste is chemically stable and not biodegradable, the exact properties contributing to the
pervasiveness of plastic products, the waste can persist in the environment for hundreds of years,
taking up more landfill space and threatening the ecosystem.3,5 An increasing number of studies
focus on the impact of the plastic waste on the environment, particularly the effects of
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Chapter 1
microplastic debris (smaller than 5 mm plastic waste) on wildlife.3,5 On the other hand,
biodegradable and biocompatible polymeric materials, which have been of great interest for
biomedical applications, can offer a feasible alternative,6 and there have been growing efforts to
design and synthesize biodegradable polymers.6-9 Natural polymers, such as polysaccharides and
proteins, and synthetic polymers containing bonds that are hydrolytically and/or enzymatically
sensitive in their backbones are (potentially) biodegradable.7,8 For instance, poly(anhydrides),
poly(esters) and poly(amides) are promising candidates for biodegradable polymers, as they contain
hydrolyzable bonds.6,10 Biomass can act as a renewable source of not only natural polymers (e.g.,
polysaccharides) but also monomers of synthetic biodegradable polymers (e.g., lactones, polyols,
dicarboxylic acids, amino acids, etc.).8,9
In conclusion, biomass can play a crucial role in solving these two grand challenges and serve as
the foundation for a sustainable future.
2. Chemocatalytic synthesis of mono- and dicarboxylic acids and esters from
biomass-derived molecules
In biorefinery, biomass can be transformed into a wide range of compounds for fuels and
chemicals.11 Among all the available biomass, including starch, fats and vegetable oils,
lignocellulosic biomass is the most abundant. Particularly, lignocellulosic biomass does not
compete with food for land use and is cheap as it is normally produced as waste from agriculture
and paper industry.12 Therefore, the valorization of lignocellulose has attracted considerable
attention.8,11,13
Lignocellulose mainly consists of 35–50% cellulose, 20–35% hemicellulose and 10–25% lignin,8
among which cellulose is a crystalline polymer with glucose units connected via β-1,4-glycosidic
bonds.8,11,13 In principle, hydrolysis of cellulose into glucose is the first step of cellulose valorization.
A variety of platform molecules can be produced via further transformation of glucose. Scheme 1
shows the top value-added chemicals from biomass identified by the U.S. Department of
Energy.14 Depending on the reaction conditions and catalysts, glucose can be then
chemocatalytically converted into different compounds, e.g., sorbitol via hydrogenation, gluconic
acid via oxidation, isomerization into fructose and then dehydration into 5-hydroxymethylfurfural,
which can be further converted into levulinic acid and formic acid via hydrolysis; alternatively,
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