时间：2017-12-22 10：00 星期五
Di Wu is an Assistant Professor in the Gene and Linda Voiland School of Chemical Engineering and Bioengineering at Washington State University (WSU). He is the founding Director of the Alexandra Navrotsky Institute for Experimental Thermodynamics (AlexInstitute) and an affiliate faculty member in the Department of Chemistry, Materials Science & Engineering Program and the Institute for Nuclear Science and Technology at WSU. He earned his B.S. from Zhejiang University, China in 2006, M.S. from the University of Akron in 2008, and Ph.D. from the University of California, Davis in 2012, all in Chemical Engineering. He was also a postdoctoral fellow at the Peter A. Rock Thermochemistry Laboratory and NEAT ORU at the University of California, Davis from 2013 to 2016. His research interests include physics and chemistry of material surfaces, catalysis, porous material synthesis, nanogeoscience and nanotechnology.
During the past few decades, advances in interfacial chemistry at the molecular level are shaping our world by playing crucial roles in balancing global scale energy crisis and critical environmental concerns. However, systematic investigations into the binding energies, site distribution and their correlations with the molecular level surface assemblages and structures at interfaces and in nanopores are rarely carried out and documented. In this presentation, I introduce my experimental studies on energetics of molecule – material interactions over the last five years. I demonstrate how thermochemistry reveals crucial energetic insights into a series of molecule – material interactions relevant to carbon capture and sequestration, energy production, materials design and synthesis, heterogeneous catalysis and nanogeoscience. Specifically, calorimetric methodologies developed and applied include direct gas adsorption calorimetry, near room temperature solvent immersion/solution calorimetry, and high temperature oxide melt solution calorimetry. Using these unique techniques, I present the thermodynamic complexity of carbon dioxide capture on metal – organic framework (MOF) sorbents with built-in and grafted nucleophilic functional groups (-OH and -NH2). These studies reveal that carbon dioxide adsorption on functionalized MOFs is a complex process involving multiple thermodynamic factors reflecting changes in surface phase and structure, chemical bonding and degree of disorder as temperature and gas loading vary. The fundamental insights obtained may help optimize the design, synthesis and application of MOF-based carbon dioxide sorbents for carbon capture and sequestration.
On the other hand, I also explore the energetics of interaction and competition between small molecules (water, carbon dioxide, simple and complex organics) and inorganic materials (calcite, silica, alumina, zirconia, uranium, zeolites and mesoporous frameworks), at interfaces and in nanopores. Combined with spectroscopic, diffraction, electron microscopic and computational techniques, the energetics of gas/liquid – solid interactions can be correlated with specific bonds, molecular configurations and nanostructures. Though the energetic evolves continuously from weak association to strong bonding to classical capping, distinct regions of rapidly changing stepwise energetics often separate the different regimes. These phenomena are closely related to the properties of inorganic material surfaces (hydrophobicity and acidity/basicity), to the framework architectures, and to the chemical nature of adsorbate molecules. The direct thermodynamic insights reinforce our understanding of complex molecule – material interactions in chemical industries, materials science, nanogeoscience and natural environments, including heterogeneous catalysis, separation, biomineralization, contaminant and nutrient transport, carbonate formation, and water – organic competitions on material/mineral surfaces.