Production of para-methylstyrene and para-divinylbenzene from furanic compounds

2017 Spring Symposium

Molly Koehle and Raul Lobo, Chemical and Biomolecular Engineering, University of Delaware, Newark, DE

Abstract – Of the three isomers of methylstyrene, para-methylstyrene is highly desirable because it yields polymers with superior properties over polystyrene and mixed poly-methylstyrene [1]. However, controlling the substitution of methylstyrene via direct acylation or alkylation of toluene is difficult because even though the para isomer is favored, meta and ortho isomers are also formed [1, 2], and separation of the isomer mixture is very difficult due to their nearly identical properties.

The Diels-Alder cycloaddition and dehydration of substituted furans with ethylene is a plausible route to p-methylstyrene since it is inherently selective to para aromatic species. We have successfully developed a three-step catalytic route to p-methylstyrene from methylfuran (Scheme 1) at high yield and very high isomer selectivity. The process uses Friedel-Crafts acylation, selective reductions with hydrogen and Diels-Alder cycloaddition with ethylene. The raw materials—furans, ethylene and acetic acid—can all be derived from biomass [3,4], thus allowing ‘green’ styrene production from renewable carbon sources. This approach has also been extended to the production of p-divinylbenzene. As the acylation step is known to be catalyzed by Lewis acids, recent work has focused on studying this step on Brønsted and Lewis acid zeolites and will be presented as well.

Scheme 1: Production of para-methylstyrene from methylfuran

[1] W.W. Kaeding and G.C. Barile, in: B.M. Culbertson and C.U. Pittman, Jr. (Eds.), New Monomers and Polymers, Plenum Press, New York, NY, 1984, pp. 223-241.
[2]“Aromatic Substitution Reactions.”
[3] A.A. Rosatella; S.P. Simeonov; R.F.M. Frade, R.F.M..; C.A.M. Afonso, Green Chem., 13 (2011) 754.
[4] C.H. Christensen; J. Rass-Hansen; C.C. Marsden; E. Taarning; K. Egeblad, ChemSusChem, 1 (2008) 283.

Biography – Molly obtained her B.S. in Chemical Engineering from the University of Pittsburgh and her M.S. in Chemical Engineering from the University of Connecticut. She has worked at the Catalysis Center for Energy Innovation in Prof. Raul Lobo’s group since 2013. Her work focuses on transformations of biomass to fuels and chemicals with Bronsted and Lewis acid zeolites.

The mechanism of CO2 reduction over Pd/Al2O3: a combined steady state isotope transient kinetic analysis (SSITKA) and operando FTIR investigation

2017 Spring Symposium

Xiang Wang, Hui Shi and János Szanyi, Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA

Abstract – Understanding the critical steps involved in the heterogeneous catalytic CO2 reduction has attracted a lot of attention recently. In order to fully understand the mechanism of this reaction the determination of both the rate-determining steps and reaction intermediates are vital. Steady-State Isotopic Transient Kinetic Analysis (SSITKA) is one of the most powerful techniques used to investigate the elementary steps under steady-state reaction conditions. This technique provides valuable information on mean resident lifetime of surface intermediates, surface concentrations of adsorbed reactant species and an upper bound of the turnover frequency. Coupling SSITKA with operando-FTIR spectroscopy allows us to discriminate between active and spectator species present on the catalytic surface under steady state reaction conditions.  In the present work operando SSITKA experiments coupled with transmission FTIR, mass spectrometry (MS) and gas chromatography (GC) were performed to probe both the chemical nature and kinetics of reactive intermediates over a Pd-Al2O3 catalysts and provide a clear mechanistic picture of the CO2 hydrogenation reaction by revealing the rate-determining steps for CH4 and CO production.

Figure 1 shows normalized real-time signals for the decay and increase of methane (a) and carbon-monoxide (b) in the effluent at 533 K reaction temperature after the feed gas was switched at 0 s from CO2/H2/Ar mixture to 13CO2/H2 mixture.  With increasing temperature, the decay of CH4 and CO get faster.  By integration under the decay curves , the mean surface-residence times CH4 and  CO), the abundance of adsorbed surface intermediates leading to CH4 and CO products  CH4 and  CO) at 533-573 K were calculated. At low temperature, CO2 methanation is slower than the reverse water-gas shift reaction, but became faster as the temperature was increased over 563 K.  The similar apparent activation energies obtained for the hydrogenation of adsorbed CO and for the formation of CH4 indicates that the hydrogenation of CO is the rate-determining step during the CO2 methanation reaction. Moreover, the similar apparent activation energies estimated for the consumption of adsorbed formates (FTIR) and for the formation of CO (MS), indicates that the H-assisted decomposition of formates is the rate determining step in the reverse water gas shift reaction.  The rate-determining step for CO formation is the conversion of adsorbed formate, while that for CH4 formation is the hydrogenation of adsorbed carbonyl. The balance of the hydrogenation kinetics between adsorbed formates and carbonyls governs the selectivities to CH4 and CO. We applied this knowledge to design catalysts and achieved high selectivities to desired products. 

Figure 1. Normalized response of (a) CH4 and 13CH4 products and (b) CO and 13CO products as functions of time.

Biography – Dr. Szanyi`s research is focused on surface science, spectroscopy and kinetic studies on heterogeneous catalytic reaction systems aimed at understanding structure-reactivity relationships. In particular, he is interested in understanding the mechanistic consequences of very high (atomic) metal dispersion on different support materials. Using a series of ensemble averaged spectroscopy methods he investigates the fundamental properties of metal atoms and small metal clusters prepared under well controlled UHV conditions. These results provide information on the energetics of the interactions between highly dispersed metals and selected probe molecules. Applying in situ RAIR spectroscopy they study the binding configurations of adsorbates to metals, and identify surface species present on the metal and support materials under elevated reactant pressures. Simultaneously, they are conducting detailed kinetics and operando spectroscopy measurements on model high surface area supported metal catalysts using flow reactors and SSITKA/FTIR/MS techniques. These measurements provide detailed kinetic information together with surface speciation that allow them to greatly enhance our mechanistic understanding of heterogeneous catalytic systems, in particular the reduction of CO2. Dr Szanyi is also involved in research related to the fundamental understanding of automotive emission control catalysis, conducting research in selective catalytic reduction of NOx on zeolite-based catalysts, low temperature NO and CO oxidation on metal oxides, and low temperatures NOx and HC storage in zeolites.

Design of complex metal/metal-oxide heterogeneous catalytic materials for energy and chemical conversion

2017 Spring Symposium

Eranda Nikolla, Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI

Abstract – Dwindling fuel resources and high levels of CO2 emissions have increased the need for renewable energy resources and more efficient energy conversion and storage systems. In this talk, some of our recent work on designing efficient (active, selective and stable) catalytic systems for energy and chemical conversions will be discussed. First, I will talk about our work on designing layered nickelate oxide electrocatalysts for electrochemical oxygen reduction and evolution reactions. These processes play an important role in fuel cells, electrolyzers and Li-air batteries. We have utilized density functional theory (DFT) calculations to identify the factors that govern the activity of nickelate oxides toward these processes. Using a reverse microemulsion approach we demonstrate an approach for synthesizing nanostructured nickelate oxide electrocatalysts with controlled surface structure. These nanostructures are thoroughly characterized using atomic-resolution high angle annular dark field (HAADF) imaging along with electron energy-loss spectroscopy (EELS) performed using an aberration corrected scanning transmission electron microscope (STEM). Controlled kinetic isotopic and electrochemical studies are used to develop structure/performance relationships to identify nickelate oxides with optimal electrocatalytic activity. Secondly, I will discuss our efforts on designing efficient catalytic systems for biomass conversion processes. Development of active and selective catalysts for biomass conversion is critical in realizing a renewable platform for fuels and chemicals. I will highlight some of our recent work on utilizing reducible metal oxide encapsulated noble metal catalytic materials to promote hydrodeoxygenation (HDO) of biomass-derived compounds. We show enhancement in HDO activity and selectivity due to the encapsulation of the metal nanoparticles by an oxide film providing high interfacial contact between the metal and metal oxide sites, and restrictive accessible conformations of aromatics on the metal surface.

Biography – Eranda Nikolla is an assistant professor in the Department of Chemical Engineering and Materials Science at Wayne State University since Fall 2011. Her research interests lie in the development of heterogeneous catalysts and electrocatalysts for chemical conversion processes and electrochemical systems (i.e., fuel cells, electrolyzers) using a combination of experimental and theoretical techniques. Dr. Nikolla received her Ph.D. in Chemical Engineering from University of Michigan in 2009 working with Prof. Suljo Linic and Prof. Johannes Schwank in the area of solid-state electrocatalysis. She conducted a two-year postdoctoral work at California Institute of Technology with Prof. Mark E. Davis prior to joining Wayne State University. At Caltech she developed expertise in synthesis and characterization of meso/microporous materials and functionalized surfaces. Dr. Nikolla is the recipient of a number of awards including the National Science Foundation CAREER Award, the Department of Energy CAREER Award, 2016 Camille Dreyfus Teacher-Scholar Award and the Young Scientist Award from the International Congress on Catalysis.

Mechanisms and Materials for Alkaline Hydrogen Electrocatalysis

2017 Spring Symposium

Maureen Tang, Chemical and Biological Engineering, Drexel University, Philadelphia, PA

Abstract – Hydrogen is a potential low cost, scalable energy storage medium for renewable electricity generation. More importantly, study of the hydrogen electrode reactions has led to the discovery of many of the fundamental concepts in electrochemistry and electrocatalysis. It has long been recognized that the reaction rates of the hydrogen oxidation and hydrogen evolution reactions (HOR and HER) are slower in basic than acidic electrolytes, even though the surface intermediate of adsorbed hydrogen is independent of solution pH. Understanding the root of this observation is critical to designing catalysts for a multitude of electrochemical reactions with relevance to energy conversion and storage. In this work, we undertake both applied and fundamental efforts to understand the mechanisms and develop low-cost, active catalysts for the hydrogen reactions in base.

In the first part of the talk, we utilize a theory-guided approach to develop nickel-silver catalysts for alkaline hydrogen evolution and oxidation. Density-functional-theory calculations predict these alloys will be active for hydrogen evolution and oxidation. To circumvent the thermodynamic insolubility of these two metals and isolate catalytic activity, we employ an uncommon physical vapor codeposition synthesis. Our measurements show that the alloy is indeed more active for hydrogen evolution than pure nickel. In the second part of the talk, we examine specifically the hypothesis that water orientation governs the rate of hydrogen adsorption and thus the overall HER/HOR kinetics by modulating the potential of zero charge of oxide supports in acid and base. Finally, we combine microkinetic modeling and single-crystal measurements to determine if adsorbed hydroxide functions as an active intermediate or spectator in the reaction. The results of these studies highlight the importance of kinetic barriers, as well as adsorption energies, and contribute to resolving a long-standing paradox in electrocatalysis and surface science.

Biography – Maureen Tang joined the faculty of Chemical and Biological Engineering at Drexel University in Fall 2014. She received her B.S. in Chemical Engineering from Carnegie Mellon University and her Ph. D. from the University of California, Berkeley. While at Berkeley, she received a NSF Graduate Research Fellowship, an NSF East Asia Pacific Summer Fellowship, and the Daniel Cubiciotti Student Award of the Electrochemical Society. Dr. Tang has completed postdoctoral work at Stanford University and research internships at Kyoto University, the University of Dortmund, and Dupont. Her research at Drexel develops materials, architectures, and fundamental insight for electrochemical energy storage and conversion.

Zeolite Catalysis with a Focus on Downstream Refining Applications

2017 Spring Symposium

C.Y. Chen, Chevron Energy Technology Company, Richmond, CA

Abstract – Zeolites have been important catalysts for the refining and petrochemical industries and other applications. The use of organo-cation template molecules to provide structure direction has given rise to a number of novel zeolites in recent years, leading to breakthroughs in zeolite synthesis and providing an impetus in developing new process chemistry. As a consequence, the understanding of zeolite structures and the structure-property relationships has become not only of basic academic interest but also one of the most critical tasks in bringing the industrial applications of these materials to successful fruition.

In this paper I will first present a brief overview of Chevron’s zeolite R&D. Then the emphasis will be placed on zeolite catalysis for downstream refining applications such as hydrocracking, hydroisomerization and MTO (methanol to olefins). Here the characterization of zeolites via catalytic test reactions and physisorption plays an important role. The hydrocracking and hydroisomerization of paraffins such as n-hexane, n-decane and n-hexadecane as well as MTO will be discussed as examples for the investigation of the catalytic properties of a series of zeolites (e.g., Y, mordenite, ferrierite, ZSM-5, ZSM-12, ZSM-22, ZSM-48, TNU-9, SSZ-25, SSZ-26, SSZ-32, SSZ-33, SSZ-56, SSZ-57, SSZ-75, SSZ-87 and SSZ-98) and some new examples of shape selectivities of zeolite catalysis will be demonstrated. Furthermore, our studies on the vapor phase physisorption of a series of hydrocarbon adsorbates with varying molecule sizes for a wide spectrum of zeolite structures will be reported. Catalytic test reactions and vapor phase hydrocarbon adsorption together also provide useful information for the determination of zeolite structures.

The author thanks Chevron Energy Technology Company for support of zeolite R&D, especially S.I. Zones, R.J. Saxton and G.L. Scheuerman.

Biography – C.Y. Chen is a senior staff scientist and technical team leader in the Catalysis Technology Department of Chevron Energy Technology Company located in Richmond, California. He is a zeolite scientist by training and has been working at Chevron for the past 22 years in zeolite research projects involving synthesis, modification, characterization, catalysis, adsorption and commercialization. He received his Diplom in Chemical Engineering from the University of Karlsruhe, Germany and Ph.D. in Chemistry from the University of Oldenburg, Germany with Prof. Jens Weitkamp. Then he was a postdoc at Virginia Tech and Caltech with Prof. Mark Davis. He is also an adjunct professor in the Department of Chemical Engineering at the University of California at Davis.

Synthesis of Zincosilicate Catalysts for the Oligomerization of Propylene

2017 Spring Symposium

Mark Deimund, ExxonMobil Research and Engineering Company, Annandale, NJ

Abstract – Two zincosilicate molecular sieves (CIT-6 and Zn-MCM-41) were synthesized and ion-exchanged with nickel, allowing them to act as catalysts for the oligomerization of propylene into C3n products (primarily C6 and C9 species). For performance comparison to aluminosilicate materials, two zeolites (high-aluminum beta and zeolite Y) were also nickel exchanged and utilized in the oligomerization reaction.

CIT-6 and the high-aluminum zeolite beta (HiAl-BEA) both have the *BEA framework topology, allowing for comparison between the zinc and aluminum heteroatoms when exchanged with nickel, as the former gives two framework charges per atom, while the latter gives only one. Ni-CIT-6 and Ni-Zn-MCM-41 enable the comparison of a microporous and a mesoporous zincosilicate. The Ni2+ ion exchanged onto zeolite Y has been previously reported to oligomerize propylene and is used here for comparison.

Reaction data are obtained at 180°C and 250°C, atmospheric pressure, and a WHSV = 1.0 h-1 in a feed stream consisting of 85mol% propylene, with the balance inert. At these conditions, all catalysts are active for propylene oligomerization, with steady-state conversions ranging from 3-16%. With the exception of Ni-HiAl-BEA, all catalysts exhibit higher propylene conversions at 250°C than 180°C. Both *BEA topology materials exhibit similar propylene conversions at each temperature, but Ni-HiAl-BEA is not as selective to C3n products as Ni-CIT-6. Zincosilicates demonstrate higher average selectivities to C3n products than the aluminosilicates at both reaction temperatures tested. Hexene products other than those expected by simple oligomerization are also present, likely formed by double-bond isomerization catalyzed at acid sites.

Additionally, both of the aluminosilicate materials catalyzed cracking reactions, forming non-C3n products. The reduced acidity of the zincosilicates relative to the aluminosilicates likely accounts for the higher C3n product selectivity of the zincosilicates. Zincosilicates also exhibited higher linear-to-branched hexene isomer ratios when compared to the aluminosilicates. The mesoporous zincosilicate exhibits the best reaction behavior (including C3n product selectivity: approximately 99% at both temperatures for Ni-Zn-MCM-41) of the catalytic materials tested here.

From Deimund, MA, et al. ACS Catal., 2014, 4 (11), pp 4189–4195. DOI: 10.1021/cs501313z

Biography – Originally from Oklahoma City, Oklahoma, Mark attended Texas A&M University where he earned his undergraduate degree in chemical engineering. He then attended the University of Cambridge for his MPhil, conducting research into the formation of protein deposits in brain cells as a means to better understand the onset of Alzheimer’s and other neurodegenerative diseases. Upon completion of this degree, he began his PhD work at the California Institute of Technology in the area of molecular sieve synthesis and reaction testing under Professor Mark E. Davis. Currently, he works as a researcher at ExxonMobil Research and Engineering Company in Annandale, NJ.

Science and Technology of Framework Metal-Containing Molecular Sieves Catalysts

2017 Spring Symposium

Laszlo Nemeth, Department of Chemistry and Biochemistry, University of Nevada Las Vegas

Abstract – Since the discovery of titanium silicalite (TS-1) more than 30 years ago framework metal-containing molecular sieves have become an important class of catalyst, finding application in several industrial processes. Incorporation of titanium, gallium, iron, tin and other elements into molecular sieves frameworks has led to both scientific progress and engineering innovations in catalysis. As a result of these developments, framework metal-containing zeolites have been implemented in the preceding decade in new commercial, byproduct-free green processes, which have improved sustainability in the chemical industry. Based on a comprehensive analysis of the recent literature including patents, this review is a summary of the current knowledge of the science and technology of framework metal-containing molecular sieves. The synthesis of these materials is summarized, followed by an account of state-of-the-art characterization methods. The key catalytic chemistries, which can be classified into oxidation reactions such as olefin epoxidation, aromatic hydroxylation and ammoximation, and Lewis acid-catalyzed reactions, are discussed. Mechanisms proposed for these transformations are reviewed, together with the theoretical and modeling tools applied in this context. An overview of the commercial technologies associated with the use of framework metal-containing molecular sieves ( Titanium and Gallium Molecular sieves) materials will be presented. The paper will be discuss the current activity on framework Tin Beta Zeolite, which shown unique “Zeoenzyme” selectivities in multiple applications. Some new chemistry using Sn-zeolites will be presented also to produce new product from biomass.

Biography – Laszlo Nemeth earned a Bachelor’s Degree in Chemistry and Doctor of Science in chemical engineering from University of Debrecen, Hungary.

Upon graduation he was assistant professor in Department of Chemical Technology at same University and later scientist/ manager at Hungarian High Pressure Institute, Hungary.

UOP invited him to join to Corporate Research in Des Plaines, IL, He worked for UOP LLC a Honeywell Company 23 years as senior research associate, with joint appointment as an adjunct professor at Chemical Engineering Department of University of Illinois at Chicago.

During his research career at UOP he was principal investigator of multiple successful projects in the area of material science, adsorption and catalysis. His expertise also includes zeolite application for UOP’s catalytic processes, metal-zeolites, solid and liquid superacids, hydrogen peroxide synthesis and new applications.

Laszlo joined the Chemistry and Biochemistry Department of University of Nevada Las Vegas in 2015 as a research professor. Currently he is working on bimetallic-zeolite synthesis and applications, Lithium Ion Battery recirculation, and develop new Thermochromic nanomaterials.

He spent his sabbatical with George Olah (Nobel Laureate) and Avelino Corma (ITQ Spain).

Dr. Nemeth was awarded with Stein Star award and Honeywell’s excellence in Innovation. He published 50+ papers and 90+ patents.