报告时间：2019年11月27日（星期三）上午8:30-10:30　　

报告地点：化工楼四楼会议室

报告人：Prof. Ryan O'Hayre, Colorado School of Mines-Metallurgical and Materials Engineering

　　报告摘要：

　　Perovskite oxides are of great scientific interest due to their compositional versatility and the resulting breadth of physical properties they exhibit. They are widely studied for numerous applications including fuel cells, magnetoresistors, multiferroics, chemical looping, and solar thermochemical hydrogen production (STCH). Currently, there are several hundred confirmed, experimentally synthesized inorganic perovskites. However, density functional theory (DFT) and machine learning (ML) screening efforts suggest that there are hundreds of stable perovskite or perovskite-related oxides remaining to be discovered and synthesized. Furthermore, because the perovskite lattice can generally accommodate significant concentrations of various A and B-site dopants, the range of possible multi-doped, perovskite solid-solution compositions (e.g. ABO₃ → A_xA_1-x'B_yB_1-y'O_3-d and so on) is virtually limitless. With such vast degrees of compositional freedom, how can we guide the design of new compositions to target specific properties or applications of interest?

　　In this presentation, we will discuss two clean energy-related application areas (solar thermochemical water splitting and intermediate temperature fuel cells) where we are combining high-throughput computation and high-throughput experiment to accelerate the search for new redox-active perovskite materials and to improve our scientific understanding of the composition-property-performance relationships to guide future optimization.

　　For solar thermochemical water splitting (STCH), we have implemented a high-throughput DFT-based screening strategy to identify existing and new redox-active oxides that may be promising high-temperature water-splitters based on pass/fail tests of several thermodynamic criteria. In parallel, we use high-throughput experimental screening methods to rapidly validate promising compositional spaces. Together, these techniques have enabled us to discover several promising new STCH-active oxides, including a new, previously unknown layered perovskite with remarkable water-splitting activity.

　　For fuel cell applications, we have recently developed a remarkable new redox-active oxide electrode based on a multi-doped perovskite, BaCo_0.4Fe_0.4Zr_0.1Y_0.1O_3-δ (BCFZY4411), that catalyzes both the oxygen evolution and oxygen reduction reactions in ceramic fuel cells and electrolyzers. While this oxide exhibits excellent properties, it represents only one point in the quaternary Co-Fe-Zr-Y space that describes the possible B-site compositions of the BCFZY system. We have begun to explore this space via high-throughput experimentation using combinatorial pulsed laser deposition coupled to high-throughput characterization tools, to allow spatially-resolved composition and property measurements of these films under various conditions. This system produces large datasets (we have already characterized more than 1000 distinct compositions within the BCFZY system) that are particularly well-suited to an informatics approach. Thus, we have partnered with Citrine Informatics, an industry leader in materials informatics, to extract insight and construct meaningful models from these data based on a set of chemical “features” or descriptors. Initial results show that the models accurately fit and predict trends in the data, suggesting that the chemical features provide an appropriate basis set to describe these materials' behavior. We are now using these models to pinpoint the optimal composition within the BCFZY system and understand property-feature relationships.

　　报告人简介：

　　Prof. O'Hayre's group at the Colorado School of Mines develops new materials and devices to enable alternative energy technologies including fuel cells and solar cells. Current fundamental research interests extend to aspects of high-temperature catalysis, electrochemistry, solid-state-ionics, electronic and ionic oxides.  Prof. O'Hayre is lead author of Fuel Cell Fundamentals, the world's best-selling textbook on fuel cell science and technology (translated into both Chinese and Korean) and has published >130 peer-reviewed publications in the field, including papers in Science and Nature, as well as several patents and book chapters. He has received several young-investigator research and teaching honors including the 2009 Presidential Early Career Award in Science and Engineering (PECASE), the US's top honor for early-career scientists and engineers.

　　联系人：504组 王卫平

　　联系电话：84379301