Catalysis and Surface Chemistry
Research groups working in catalysis and surface chemistry in our departments are addressing societal challenges in the areas of energy conversion, the production of commodity products and chemicals, and environmental protection. We develop methods to transform biomass and fossil resources into fuels and chemicals; convert CO2 into fuels and chemicals; design environmentally benign industrial chemistries; harness solar and electrochemical energy; and create more effective catalysts for numerous applications. Faculty and graduate students in our department are tackling these projects with multidisciplinary approaches that combine experiment, theory and simulations and often work in collaborative teams with researchers in other departments, within industry, and across the world. Our work has generated numerous patents, established start-up companies (operated by our graduates), and commercialized products and processes. These technologies were developed in our department by work that spans fundamental research, proof of principle demonstrations, and finally, product development. Our graduates who have participated in these projects are aggressively recruited for industrial and academic positions.
Catalytic production of fuels and chemicals
As our traditional energy and commodity chemical resources become increasingly scarce, more selective processes and catalysts and renewable feed stocks and energy sources must be developed. Researchers in the Flaherty Lab are exploring approaches to better utilize building block derived from biomass (e.g., ethanol, furans) to create advanced fuels and platform chemicals that can replace petrochemicals for the manufacture of polymers. Exemplary reactions include selective addition reactions that oligomerize small molecules into aromatic chemicals and the targeted rupture of individual bonds within large molecules to produce valuable fatty alcohols and linear alpha olefins. These projects involve the simultaneous application of advanced in situ spectroscopy and kinetic analysis to understand surface chemistry and the application of catalyst design and reaction engineering principles to control notoriously difficult reactions and make products that society needs.
In related work, the Guironnet Lab harnesses the remarkable catalytic properties of homogeneous catalysts (single metal atom complexes with highly tailorable reactivity and selectivity) to perform difficult hydrocarbon transformations including tandem and cascade reactions. Such reactions are hard to achieve with other types of catalysts that lack the necessary selectivity, but integrating homogeneous catalysts into processes requires finesse. To address this challenge, these catalysts have been incorporated into a novel reactor that allows researcher to gain further insights into the relationship between selectivity, reactivity and stability of these organometallics complexes while they operate. This approach provides direct information that cannot be obtained by other methods. The lessons learned from this work will guide the development of the next generation of catalysts that will be synthesized by Illinois researchers.
Photocatalysis, Environmental Protection and Remediation
Solutions to the energy challenges society faces will increasingly be met by renewable sources of energy including the transformation of sunlight into chemical fuels and electricity. At Illinois, we are working to understand how to design materials that can convert water and sunlight into hydrogen as well as systems that make fuels from CO2 captured from the atmosphere.
Researchers in the Seebauer Laboratory apply their expertise in semiconductor physics to conceptualize and design improved photocatalysts. Their novel approach has led to the synthesis of layered semiconductor heterojunctions (e.g., TiO2-Sr2RuO4) that combine materials with excellent capabilities to absorb light with those that are efficient catalysts that make use of the excitons to perform chemistry (e.g., water splitting). Building on this idea, the group is using band engineering strategies adapted from the microelectronic industry to improve the photocatalytic efficiency of low-cost, abundant materials.
One of the areas of focus in the Kenis Laboratory is the production of carbon-neutral fuels and chemical from the reduction of CO2 captured from power plants and chemical manufacturing facilities using excess electrical power that is available on the grid. Their work lies at the intersection of electrochemistry and reaction engineering to build reactors and integrated systems that efficiently convert CO2 into useful products. Researchers apply engineering design principles and technoeconomic analyses to determine useful strategies. They also construct uniquely structured microreactors that leverage novel hydrodynamic phenomena that emerge at the microscale.
The Flaherty Lab seeks to replace harmful chlorinated oxidants that are used on a massive scale in the manufacture of chemicals. The elusive nature of chlorinated compounds allows them to escape from chemical plants after which they pose a hazard to human health and the environment. Work on this topic centers on the direct synthesis of H2O2 (a environmentally benign alternative to chlorine) and the use of H2O2 for the epoxidation of olefins to produce precursors for plastics and the oxidation of sulfides to produce clean burning fuels. Researchers use deep understanding of surface chemistry principles and catalytic chemistry to propose, synthesize and test new catalysts for these reactions. In situ spectroscopy and kinetic analysis provide direct insight to the mechanisms of these reactions and enable the rational design of more selective catalysts.
Current separation technologies often require large energy or chemical consumption, and can result in significant secondary pollution. Through a combination of materials design and electrochemical engineering, the Su Lab develops advanced separation processes that reduce energetic costs, maximize molecular selectivity, and minimize chemical input. We are interested in the extraction, transformation and recovery of minority species from various fluid streams using electrochemical processes. For example, we are interested in the remediation of micropollutants of concern, where the goal is to remove them at ultra-dilute concentrations from water, and reduce their toxicity through electrochemical transformations. In general, our work has implications for on-site water purification in remote areas, industrial waste treatment and resource recovery, and the downstream purification of fine chemical products.
Surface Science and Interfacial Phenomena
Molecules dwelling at phase boundaries play a critical role in determining the material properties. Interfacial phenomena are incredibly important and must be understood to develop useful micromaterials and thin coatings for a variety of applications. At Illinois, we employ experimental, computational, and theoretical approaches to push the boundary of our understanding of interfacial phenomena. With such knowledge, the Diao group manipulates interfacial structure, material composition, and transport processes to design and create new functional materials with desirable electronic, optical, reactive and mechanical properties. Their work leads towards the development of new, scalable methods to manufacture flexible electronic devices (e.g., microchips) and next-generation organic solar cells.
At the fundamental level, the Su Lab focuses on the molecular engineering of electrochemical interfaces, aiming to control binding affinity and reversibility towards target analytes. Redox-active materials, either crystalline or polymeric, have traditionally been interesting platforms for energy storage and electrocatalysis. Here at UIUC, we seek to discover new modes of interfacial interaction for materials synthesis and separation processes. A major aim of our group is to create conductive, redox-active nanostructures that can enable molecular selectivity and high electrochemical performance. These fundamental studies are expected to lead to greener and more efficient approaches for chemical processing.
Electrocatalysts and Fuel Cells
Fuel cells generate electrical power from chemical fuels with efficiencies that are substantially greater than thermal combustion processes (e.g. gasoline and diesel engines) and with less harmful emissions. However, fuel cells are used surprisingly less frequently than expected, because the electrocatalysts needed for these systems are composed of expensive and rare metals (e.g., Pt). The Yang group combines knowledge of electrochemistry and synthetic expertise to make more reactive yet cheaper electrocatalysts by combining two or more metals into precisely structured nanocrystals. Recent work on Pt-Ni and Pt-Ag structures (among others) shows that reactivity of these structures reflects the precise location of each type of atoms in the nanocrystal surfaces. Their group applies electrochemical techniques, environmental transmission electron microscopy, and other spectroscopic methods to characterize these structures and to watch them operate.