Biomass and Natural Gas Valorization by Zeolite Catalysis

Meeting Program – February 2017

Raul Lobo
Raul Lobo
Claire D. LeClaire professor of Chemical and Biomolecular Engineering,
University of Delaware

 

Abstract – Prof. Lobo’s research group is interested in developing and understanding catalysis systems to enable the transformation abundant, inexpensive and—when possible—renewable carbon sources into feedstocks for the chemical industry. We combine expertise in materials synthesis, catalysis and kinetics, and reaction engineering to develop novel catalysts and catalytic processes that produce valuable products.

In the first part I will focus on C-C bond forming reactions that are helpful in the transformation of furans (produced from glucose or xylose by dehydration) into valuable commodity chemicals. To this end we have developed and optimized zeolite catalyst compositions to form aromatic species out of the furans via Diels-Alder reactions and Friedel-Craft acylation reactions. We will describe efforts to producing benzoic acid and α-methylstyrene from furans in high selectivity and high yield, along with the elucidation of the reaction mechanisms of these reactions.

In the second part I will discuss on-going research directed towards the development of catalysts for the selective oxidation of methane into methanol. We will show that zeolites can serve as hosts of transition metals oxide clusters (copper or iron) that are analogous to metal oxide clusters observed in a number of important enzymes such as particulate methane monooxygenase (pMMO). These clusters are capable of oxidizing methane to methanol, carbon monoxide and CO2. By selectively choosing materials that compartmentalize Cu-O clusters, we have identified zeolite structures that are able to selectively oxidize methane to methanol with very high selectivity in a three-step cyclic process. We will describe the potential and the drawbacks of transforming such cyclic process into a catalytic process for methanol production.

Despite the maturity of the field of catalysis this talk will show that tantalizing new opportunities emerge from the discovery of new catalyst structures and compositions, and from improvements in our control of the composition of metal clusters in nanoscopic environments.

Biography – Raul F. Lobo is the Claire D. LeClaire professor of Chemical and Biomolecular Engineering at the University of Delaware and Director of the Center for Catalytic Science and Technology. His research interests span the development of novel porous materials for catalysis and separations, the chemistry of zeolites, catalysis for energy and the environment, and the scientific aspects of catalyst synthesis. He has published over one hundred fifty refereed reports and he is co-inventor in three US patents. He obtained his undergraduate degree in Chemical Engineering at the University of Costa Rica in 1989 and later moved to California to pursue graduate studies in Chemical Engineering at Caltech. He worked for one year at Los Alamos National Laboratory, New Mexico as a postdoctoral fellow and he started his academic career at the University of Delaware in 1995.

Prof. Lobo has conducted research in the use of zeolites for nitrogen/oxygen separations, and carbon dioxide separations from flue gases. He has contributed to the fundamentals of zeolite nucleation and crystal growth and to the application of zeolites for a number of catalytic applications. In particular his group research helped understand the mechanisms of reaction and stability of zeolite catalysts used for the removal of NOx gases from combustion exhaust, developed catalytic materials for the transformation of biomass-derived furans into commodity aromatic molecules such as xylenes and benzoic acid and discovered materials for the selective activation of methane using copper oxide clusters.

Ciapetta Award Lecture: Novel Zeolite Catalysts for Diesel Emission Applications

Meeting Program – January 2017

Ahmad Moini
Ahmad Moini
BASF Corporation

 

Abstract – Automotive exhaust conditions present unique challenges for the design of effective catalysts. In addition to the need for catalytic activity over a wide temperature range, the catalyst must show durability towards extreme hydrothermal aging conditions. The use of zeolitic materials under such conditions is especially challenging due to the vulnerability of zeolites to steam aging. The BASF discovery of the Cu-CHA catalyst for selective catalytic reduction (SCR) of NOx demonstrated an effective balance between favorable active sites and zeolite framework durability. It also paved the way for the implementation of urea SCR as the key approach for NOx reduction in diesel vehicles. This presentation will highlight the development of Cu-CHA as the leading technology for diesel emission applications. Specific focus will be placed on the synthesis and structural features of the zeolite. In addition, there will be a discussion of specific characterization and modeling approaches focusing on the unique attributes of the metal active sites and the interaction of these metal species with the zeolite framework.

Biography – Dr. Ahmad Moini is a Research Fellow at BASF Corporation in Iselin, NJ. He obtained his Ph.D. in Chemistry from Texas A&M University, and held a postdoctoral appointment at Michigan State University. Dr. Moini started his career at Mobil Research & Development Corporation (now ExxonMobil), where he conducted research on microporous materials. With a focus on exploratory zeolite synthesis, he studied the mechanism of zeolite crystallization and the role of specific classes of organic directing agents in the formation of various zeolite frameworks. He joined Engelhard Corporation (now BASF) in 1996. Since then, his primary research interests have been in the area of materials synthesis, directed at a range of catalytic and functional applications. He applied high throughput methods for the synthesis and evaluation of catalytic materials, and used these tools for the development of new products. A significant part of his work has been directed towards catalysts for environmental applications. These efforts, in collaboration with the extended BASF team, led to the discovery and development of Cu-CHA catalyst for selective catalytic reduction (SCR) of NOx from diesel vehicles. He holds 48 US patents relating to various aspects of materials and catalyst development.

Unraveling Catalytic Mechanisms and Kinetics: Lessons from Electrical Networks

Meeting Program – November 2016

Ravindra Datta
Professor Ravindra Datta
Professor in the Department of Chemical Engineering,
Fuel Cell Center,
Worchester Polytechnic Institute

 

Abstract – Catalytic reaction networks, in general, comprise of multiple steps and pathways. While one can now readily predict kinetics of these molecular steps from first principles, there is not yet available a comprehensive framework for: 1) visualizing and analyzing these reaction networks in their full complexity; and 2) unequivocally identifying the germane steps and pathways.

Thus, we have developed an approach called the “Reaction Route (RR) Graph” approach, which allows: 1) direct enumeration of all the pathways as walks on the RR Graph; 2) thermodynamic consistence of step kinetics; 3) elucidation of dominant pathways that contribute materially to the overall flux; 4) identification of bottleneck steps in each of these pathways; and 5) development of explicit rate laws based on the electrical analogy.

The electrical network analogy is based on two aspects of RR Graphs, namely: 1) quasi-steady state (QSS) mass balance of intermediate species, the equivalent of the Kirchhoff’s Current Law (KCL) of electrical circuits; and 2) Hess’s law, or thermodynamic consistence, the equivalent of the Kirchhoff’s Potential Law (KPL), which makes RR Graphs precisely equivalent to electrical networks. Further, we define the step resistance in terms of step kinetics to make the analogy complete. The approach is described with the help of the water-gas shift example.

Biography – Ravi Datta is Professor of Chemical Engineering and Director of WPI Fuel Cell Center. He obtained his Ph.D. degree from the University of California, Santa Barbara, in 1981. From then until 1998, he was a Professor of Chemical Engineering at the University of Iowa, when he moved to WPI, and served as Chemical Engineering Department Head until 2005. Ravi’s research is focused on catalytic and electrocatalytic reaction engineering of Clean Energy, including, fuel cells, hydrogen, renewable fuels, novel catalysts, and catalytic reaction networks. He is a coauthor of 150 papers and 8 patents, and has been a mentor to 25 doctoral students.

Development of heterogeneous catalysts for the production of biomass-derived chemicals by selective C-O hydrogenolysis and deoxydehydration

Meeting Program – October 2016

Keiichi Tomishige
Keiichi Tomishige
Professor in the School of Engineering,
Tohoku University

 

Keiichi Tomishige

Abstract – Chemical composition of the feedstock from biomass and biomass-based building blocks has much higher oxygen contents than that from crude oil. It has been known that the target products such as monomers for the polymer synthesis have comparatively lower oxygen content, and the methodology for the decrease of the oxygen content is more and more important. One of effective methods is the utilization of the hydrogenolysis of C-O bonds in the substrates. For example, C3-C6 sugar alcohols (glycerol, erythritol, xylitol, and sorbitol) are also regarded as promising building blocks in the biomass refinery. If the selective hydrogenolysis of the target C-O bond among various kinds of the C-O bonds is possible, valuable chemicals such as diols, mono-ols, alkanes can be produced from biomass in high yield. ReOx-modified Ir metal catalyst (Ir-ReOx) is reported to be effective to the selective hydrogenolysis of polyols and cyclic ethers in water solvent. Ir-ReOx/SiO2 catalyzes the hydrogenolysis of glycerol to 1,3-propanediol. The hydrogenolysis of erythritol over the catalyst produces 1,4- and 1,3-butanediols. The selective hydrogenolysis of tetrahydrofurfuryl alcohol to 1,5-pentanediol also proceeds using Ir-ReOx/SiO2. In addition, the combination of Ir-ReOx/SiO2 with H-ZSM-5 gives n-alkanes and hexanols from cellulose, sugars, and sugar alcohols in high yield with the total C-O hydrogenolysis and without C-C bond dissociation and skeletal isomerization. Another interesting catalyst is ReOx-Pd/CeO2. The catalyst showed excellent performance for simultaneous hydrodeoxygenation of vicinal OH groups in various substrates. High yield (>99%), turnover frequency, and turnover number were obtained in the reaction of 1,4-anhydroerythritol to tetrahydrofuran. This catalyst is also applicable to the conversion of sugar alcohols mono-alcohols and diols are obtained in high yields from substrates with even and odd numbers of OH groups, respectively. In addition, ReOx-Au/CeO2 catalyzed the conversion of glycerol and erythritol to allyl alcohol and 1,3-butadiene in high yield (91% and 81%), respectively.

Biography – Keiichi Tomishige received his B.S., M.S. and Ph.D. from Graduate School of Science, Department of Chemistry, The University of Tokyo with Prof. Y. Iwasawa. During his Ph.D. course in 1994, he moved to Graduate School of Engineering, The University of Tokyo as a research associate and worked with Prof. K. Fujimoto. In 1998, he became a lecturer, and then he moved to Institute of Materials Science, University of Tsukuba as a lecturer in 2001. Since 2004 he has been an associate professor, Graduate School of Pure and Applied Sciences, University of Tsukuba. Since 2010, he is a professor, School of Engineering, Tohoku University.
His research interests are the development of heterogeneous catalysts for

  1. production of biomass-derived chemicals
  2. direct synthesis of organic carbonates from CO2 and alcohols
  3. steam reforming of biomass tar
  4. syngas production by natural gas reforming

He is Associate Editor of Fuel Processing Technology (2014/2-), Editorial board of Applied Catalysis A:General (2009/4-), Editorial advisory board of ACS Catalysis (2013/11-), International Advisory Board of ChemSusChem (2015/1-) and Advisory Board of Green Chemistry(2016/8-).

In Silico Prediction of Materials for Energy Applications

Meeting Program – September 2016

 
Dion Vlachos
Dion Vlachos
Elizabeth Inez Kelley Professor of Chemical
& Biomolecular Engineering and Professor of Physics,
University of Delaware

 
 
 
 
 
Abstract – In this talk, the need for new materials in various energy domains will be discussed. Multiscale simulation will then briefly be introduced as an enabling technology to address diverse engineering topics. A specific application of multiscale simulation is the prediction of macroscopic behavior from first principles. A more impactful avenue of research is how one could use multiscale modeling in reverse engineering for predicting new materials for production of energy and chemicals and energy storage. We will demonstrate how descriptor-based modeling can enable such a search of novel materials with emergent behavior and assess this framework with experiments. An outstanding question is how reliable and robust are model predictions in comparing to data and our quest for searching new materials. We will demonstrate this methodology for the specific example of ammonia decomposition for hydrogen production for fuel cells and briefly touch upon renewable chemicals and fuels from lignocellulosic biomass.
 
Biography – Dionisios (Dion) G. Vlachos is the Elizabeth Inez Kelley Professor of Chemical & Biomolecular Engineering and Professor of Physics at the University of Delaware and the Director of the Catalysis Center for Energy Innovation (CCEI), an Energy Frontier Research Center (EFRC) funded by the Department of Energy (DOE). He obtained a five-year diploma in Chemical Engineering from the National Technical University of Athens, Greece in 1987, his M.S. and Ph.D. from the University of Minnesota in 1990 and 1992 respectively, and spent a postdoctoral year at the Army High Performance Computing Research Center in Minnesota. After that, Dr. Vlachos joined the University of Massachusetts as an assistant professor, was promoted to an associate professor in 1998 and joined the University of Delaware in 2000. He was a visiting fellow at Princeton University in the spring of 2000, a visiting faculty member at Thomas Jefferson University and Hospital in the spring of 2007 and the George Pierce Distinguished Professor of Chemical Engineering and Materials Science at the University of Minnesota in the fall of 2007.

Professor Vlachos is the recipient of the R. H. Wilhelm Award in Chemical Reaction Engineering from AIChE and is an AAAS Fellow. He also received a NSF Career Award and an Office of Naval Research Young Investigator Award. He is a member of AIChE, ACS, the Combustion Institute, MRS, the North American Catalysis Society (NACS) and the Society for Industrial and Applied Mathematics (SIAM).

Dr. Vlachos’ main research thrust is multiscale modeling and simulation along with their application to catalysis, crystal growth, portable microchemical devices for power generation, production of renewable fuels and chemicals, catalyst informatics, detailed and reduced kinetic model development and process intensification. He is the corresponding author of more than 340 refereed publications with nearly 10,000 citations and has given over 200 plenary lectures, keynote lectures and other invited talks. Professor Vlachos has served as an executive editor of the Chemical Engineering Science journal and also served or currently serves on the editorial advisory board of ACS Catalysis, Reaction Chemistry & Engineering, Industrial and Engineering Chemistry Research, Applied Catalysis A: General, Proceedings of the Combustion Institute, the Open Energy and Fuels Journal, the Journal of Nano Energy and Power Research and the Journal of Chemical Engineering & Process Technology.

Insight into Supported Metal Catalyst Stability by Quantifying Thermodynamic Interactions at the Solid-liquid Interface

Meeting Program – April 2016

 
Robert Rioux
Robert Rioux
Friedrich G. Helfferich Associate Professor of Chemical Engineering
Pennsylvania State University

 
 
 
 
 
Abstract – Industrial applications of supported late transition metal catalysts demand economic and scalable synthesis of these catalysts and current synthetic methods lack precision in terms of size, shape and compositional control. Moreover, supported metal catalysts suffer from poor stability, manifested in the form of sintering (i.e., particle growth) during reaction. The proper selection of the oxide support is of great importance to ensure high dispersion, activity and selectivity of the nanoparticles. The ability of these supports to enhance the dispersion of the active metal on their surface and control their morphology and sintering kinetics is fundamentally related to the nature and strength of the metal–metal oxide interaction at the time of adsorption. In this work, we have utilized isothermal titration calorimetry (ITC), a technique capable of quantifying the thermodynamic description (ΔG, ΔH, ΔS, n (stoichiometry)) of transition metal association with a support material in a single experiment. After providing a brief introduction to ITC and methods of catalyst synthesis, we will discuss our results to quantify the electrostatic interactions between solvated transition metal ions and charged amphoteric metal oxide surface. Within this interaction-type, we have studied both refractory and reducible metal oxides. With a reducible metal oxide, ceria, we demonstrate a potentially new mechanism of adsorption, which may describe the successful stabilization of noble metals enabling maintenance of small sized nanoparticles compared to other oxide supports. In addition to ITC, bulk uptake studies have aided in quantifying the amount of metal precursor adsorbed on the support surface and equilibrium isotherms describe the uptake behavior and may provide insight for predicting long term stability of the nanoparticles. In the second half of the talk, we discuss the adsorption of transition metal oxide and hydroxide nanoparticles in the galleries of of Nb-based perovskites. ITC was used to quantitatively rank the strength of adsorption between the metal nanoparticle and their propensity to sinter, as assessed by in-situ, high-temperature transmission electron microscopy. In both examples, we will emphasize this initial interaction at the solid-liquid interface is important and conveys a history effect to the catalyst that is evident during post-processing (drying, calcination and reduction). The estimated thermodynamic parameters are expected to quantify the type of bonding at the interface, shed light on the binding mechanism and the growth and sintering kinetics of supported catalysts.
 
Biography – Robert (Rob) M Rioux is the Friedrich G. Helfferich Associate Professor of Chemical Engineering at the Pennsylvania State University. Prior to joining the Pennsylvania State University in 2008, he was a National Institutes of Health Postdoctoral Fellow at Harvard University in the Department of Chemistry and Chemical Biology working with Professor George Whitesides. He received his Ph.D. in physical chemistry from the University of California, Berkeley in 2006 working for Professor Gabor Somorjai. He holds a B.S. and M.S. degree in chemical engineering from Worcester Polytechnic Institute and the Pennsylvania State University, respectively. Since joining the Penn. State faculty, he has received a number of awards, including a DARPA Young Faculty Award, an Air Force Office of Scientific Research Young Investigator Program Award, a NSF CAREER Award and a 3M Non-Tenured Faculty Award. Research in his laboratory is currently sponsored by NSF, DOE-BES, DARPA, AFOSR, AFRL, ACS-PRF and industry. His group’s current research focus is on the development of spatially- and temporally-resolved spectroscopic techniques for imaging catalytic chemistry, single molecule methods to understand single molecule/particle catalytic kinetics and dynamics, elucidating reaction mechanisms in nanoscale systems, including catalyst synthesis, development of solution calorimetric techniques to understand catalytic processes at the solid-liquid interface and the development of base-metal catalysts for chemoselective chemical transformations, including biomass to chemicals conversion.

Identification of Active Sites for Methyl Lactate Dehydration on Faujasites

Meeting Program – March 2016

 
Bingjun Xu
Bingjun Xu
Chemical and Biomolecular Engineering
University of Delaware

 
 
 
 
 
 
 
 
Abstract – The dwindling reserve of crude oil and surge in natural gas production is rapidly changing the mix of the carbon source pool for the production of fuels and chemical feedstocks, and in turn creating shortages of several key commodity chemicals, e.g., propylene and butadiene. The shortage of certain commodity chemicals, such as propylene, drives up their prices, which in turn raises the cost of the downstream chemicals, such as acrylic acid. In this regard, lignocellulosic biomass derived feedstocks, e.g., lactic acid and its esters, can potentially bridge the gap. Currently, the commercial fermentation process using biomass-derived sugars can achieve a lactic acid (or its esters) yield of up to 90%. The absence of efficient and selective catalyst for lactic acid dehydration is the main missing link in the production of renewable acrylic acid. The primary roadblock for the rational design of catalysts for lactic acid dehydration is the lack of the mechanistic understanding of the nature of active sites and mechanistic steps leading to the selective removal of the α-hydroxyl group by dehydration. Through kinetic and in-situ spectroscopic investigations, we identify the dehydration reaction proceeds through dissociative adsorption, acid-mediated dehydration, and associative desorption steps. These mechanistic insights will guide the design of selective catalysts for this reaction.
 
Biography – Bingjun Xu is currently an Assistant Professor in the Department of Chemical and Biomolecular Engineering at University of Delaware. Dr. Xu received his Ph.D. in Physical Chemistry, advised by Prof. Friend, from Harvard University in 2011. His thesis established a mechanistic framework for oxidative coupling reactions on Au surface through surface science studies. Dr. Xu worked with Prof. Davis at Caltech on the development of a low temperature, manganese oxide based thermochemical cycle for water splitting. Upon finishing his postdoc, he joined University of Delaware in the fall of 2013. The current research interest of the Xu lab spans heterogeneous catalysis, electrocatalysis and in-situ spectroscopy.