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Catalytic oxidation of CH4 over nonprecious Ni/CeO2 catalysts has attracted wide attention. Controlling the morphology of a CeO2 support can enhance the CH4 oxidation activity without changing the catalyst composition. Herein, a series of 2 wt % Ni/CeO2 nanocatalysts with different CeO2 support morphologies (nanoparticles (P), rods (R), cubes (C)) and synthetic procedures (precipitation, sol-gel (SG)) were evaluated for their CH4 oxidation performance. The redox properties of CeO2 supports and corresponding Ni loaded catalysts were characterized by H2-temperature-programmed reduction and oxygen storage capacity (OSC) measurements. The relationship among the CeO2 morphologies, surface areas, redox properties, and CH4 oxidation activity for both CeO2 supports and Ni/CeO2 catalysts was established. The findings suggest that CeO2-R has a greater amount of surface oxygen vacancies as well as an improved OSC and CH4 oxidation activity compared to CeO2-P and CeO2-C supports. The same CH4 oxidation activity pattern was observed for the Ni containing catalysts (Ni/CeO2-R > Ni/CeO2-P > Ni/CeO2-C). Increasing the CeO2 surface area by using a sol-gel synthesis method (CeO2-SG) improved the amount of surface oxygen vacancies and CH4 oxidation performance of CeO2-SG and Ni/CeO2-SG compared to CeO2-R and Ni/CeO2-R, respectively. Finally, all studied Ni/CeO2 nanocatalysts showed improved hydrothermal stability compared to conventional Pd/Al2O3. [ABSTRACT FROM AUTHOR]

Background: The process of liver organogenesis has served as a paradigm for organ formation. However, there remains a lack of understanding regarding early mouse and human liver bud morphogenesis and early liver volumetric growth. Elucidating dynamic changes in liver volumes is critical for understanding organ development, implementing toxicological studies, and for modeling hPSC‐derived liver organoid growth. New visualization, analysis, and experimental techniques are desperately needed. Results: Here, we combine observational data with digital resources, new 3D imaging approaches, retrospective analysis of liver volume data, mathematical modeling, and experiments with hPSC‐derived liver organoids. Mouse and human liver organogenesis, characterized by exponential growth, demonstrate distinct spatial features and growth curves over time, which we mathematically modeled using Gompertz models. Visualization of liver‐epithelial and septum transversum mesenchyme (STM) interactions suggests extended interactions, which together with new spatial features may be responsible for extensive exponential growth. These STM interactions are modeled with a novel in vitro human pluripotent stem cell (hPSC)‐derived hepatic organoid system that exhibits cell migration. Conclusions: Our methods enhance our understanding of liver organogenesis, with new 3D visualization, analysis, mathematical modeling, and in vitro models with hPSCs. Our approach highlights mouse and human differences and provides potential hypothesis for further investigation in vitro and in vivo. Key Findings: We developed a new approach that enables quantitative visualization and analysis of mouse and human early liver growth by using available online databases.We identify potentially new spatial features of liver bud growth, and establish the importance of liver‐STM interactions with both imaging/analysis and a novel assay for liver bud migration.Our studies provide a visual and quantitative comparison of liver bud growth. These studies improve our understanding of mouse and human liver organogenesis [ABSTRACT FROM AUTHOR]