Abstract: Carbon dioxide (CO2) is increasingly recognized as a versatile carbon building block for the sustainable synthesis of value-added chemicals and fuels. Among the products accessible from CO2, dimethyl ether (DME) stands out as a promising alternative fuel owing to its high cetane number (~55), clean combustion characteristics, sulfur-free nature, and low emissions of NOx and carbon monoxide. DME can be readily liquefied under moderate pressures, transported using infrastructure similar to that for liquefied petroleum gas (LPG), and burns without soot formation due to the absence of carbon–carbon bonds. LPG itself is another attractive fuel that can be derived from CO2, further expanding the portfolio of carbon-neutral energy carriers. In this presentation, we highlight our recent progress in the direct, one-step hydrogenation of CO2 to fuels using bifunctional thermocatalysts. Specifically, we demonstrate the efficient conversion of CO2 and H2 to DME over a bifunctional catalyst system composed of a Cu-based catalyst for methanol synthesis and an HZSM-5 zeolite for in situ methanol dehydration. This integrated approach enables DME production within a single reactor, eliminating the need for intermediate methanol separation. In parallel, we show that LPG-range hydrocarbons can be selectively produced via one-step CO2 hydrogenation using a Cu/ZrO2/ZnO/Al2O3 (CZZA) catalyst coupled with β-zeolite. Together, these results illustrate the potential of bifunctional thermocatalytic strategies to transform CO2 into clean, high-performance fuels and contribute to a circular carbon economy.

Biography: Dr. Xinhua Liang is a professor in the Department of Energy, Environmental, and Chemical Engineering at Washington University in St. Louis. He joined WashU in August 2022 from Missouri University of Science and Technology, where he was the Linda and Bipin Doshi Associate Professor of Chemical and Biochemical Engineering and had been a member of the faculty since 2012. He attended the Chemical Engineering program at Tianjin University, earning bachelor's degree in 2001 and master's degree in 2003. He received Ph.D. in Chemical Engineering from the University of Colorado Boulder in 2008 and had three years of postdoctoral training there. Dr. Liang’s research interests are in nanostructured materials synthesis and functionalization by atomic/molecular layer deposition and applying this technology in a broad range of energy and environmental applications including catalysis, storage batteries, and gas and liquid separation.