yuriy roman mit
Zeolites and metal-organic frameworks are porous materials with unique pore structures that offer many opportunities as tunable catalysts due to their shape- and size-selectivity and the ability to precisely control chemical composition and siting. Our group has extensive experience synthesizing and characterizing these materials and testing their activity for various catalytic processes of industrial relevance, including the partial oxidation of methane, sugar isomerization, aldol condensation, and heterocycle carbonylation. Simultaneously, we are also exploring reactor engineering for the continuous synthesis of zeolites and metal-organic frameworks and machine learning approaches to zeolite synthesis.
Team members: Shuai Yuan, John Di Iorio, Sujay Bagi, Soonhyoung Kwon
Lignin is a major component of biomass that is potentially one of the largest renewable sources of valuable phenolic compounds. At present, however, lignin is viewed primarily as a waste product in the pulp and biorefinery industries because it interferes with the utilization of the carbohydrate fraction. Hence, effective lignin valorization constitutes a major challenge for the viability of second-generation biorefineries. Our group is broadly interested in this topic, with a diverse array of ongoing projects across the value chain ranging from: understanding the mechanisms of perovskite and carbide catalysts for hydrodeoxygenation of lignin-derived compounds, reactor engineering for continuous biomass processing, tandem depolymerization and upgrading processes for single-step production of various target molecules, to multiscale computational simulations of the lignification process in planta.
Team members: Bing Yan, Yanding Li, Michael Stone, Amber Phillips
Core-shell nanoparticles as next-generation electrocatalysts
Core-shell nanoparticles have emerged as a promising class of materials capable of disentangling the geometric and electronic effects that modulate noble metal electronic structure. We have developed facile syntheses of monolayer Pt shells on various transition metal carbide and nitride cores. We demonstrated that these materials featured enhanced CO tolerance during electro-oxidation reactions as a result of strong electronic interactions between the shell and the underlying core that altered the binding energy of the surface Pt-CO adsorbates. Current work is focused on applying this versatile platform towards other electrochemical reactions and developing a fundamental understanding of how electronic structure affects catalytic properties.
Team members: Kaylee McCormack, Daniel Zheng
Whereas homogeneous Grubbs and Schrock catalysts have revolutionized specialty chemical and pharmaceutical production, industrial heterogeneous metathesis processes (e.g., for gas-phase upgrading of light olefins) still rely on decades-old supported metal oxide catalysts. In this regard, a major roadblock to process and catalyst development is a lack of mechanistic understanding of the metathesis reaction over these deceptively simple materials, in contrast to the well-understood Chauvin mechanism governing homogeneous metathesis catalysts. In recent work, we have made and tested catalysts supported on tunable zeolite and metal-organic framework supports in order to explore structure-activity relationships and optimize metal-support interaction and metathesis rates.
Electrochemical Promotion of Catalysis
Electrochemical promotion of catalysis (EPOC) is a phenomenon by which the properties of a catalyst surface can be modified in situ by use of an ion-mediated, interfacial electric field. These electric fields may be leveraged to tune both the overall rates and product distributions of thermal (i.e., non-Faradaic) reactions of interest. Our group is investigating this topic by combining fundamental mechanistic studies with materials design. This is supplemented by in situ spectroscopic measurements that allow us to examine structural and electronic changes to the catalysts during polarization.
Team members: John Di Iorio, Thejas Wesley, Alexander Khechfe, Blake Johnson
Catalytic plastics upcycling
Our group has recently become interested in catalytic strategies for the depolymerization and upcycling of waste synthetic polymers (i.e., plastics) into useful fuels and chemicals. Our deconstruction efforts are part of the BOTTLE initiative, which leverages a multidisciplinary approach to create a circular plastics economy. Current research in our lab is focused on highly selective and highly active hydrogenolysis of polyolefins and the electrochemical depolymerization of polystyrene. Our experimental kinetic studies are supported by the development of relevant simulations.
Team members: Bing Yan, Julie Rorrer, Ydna Questell, Griffin Drake