For high-temperature catalytic reaction, it is of significant importance and challenge to construct stable active sites in catalysts. Herein, we report the construction of sufficient and stable copper clusters in the copper‒ceria catalyst with high Cu loading (15 wt.%) for the high-temperature reverse water gas shift (RWGS) reaction.
View Article and Find Full Text PDFThe dissociation of HO is a crucial aspect for the water-gas shift reaction, which often occurs on the vacancies of a reducible oxide support. However, the vacancies sometimes run off, thus inhibiting HO dissociation. After high-temperature treatment, the ceria supports were lacking vacancies because of sintering.
View Article and Find Full Text PDFA facile spray pyrolysis method is introduced to construct the hollow CeO-AlO spheres with atomically dispersed Fe. Only nitrates and ethanol were involved during the one-step preparation process using the ultrasound spray pyrolysis approach. Detailed explorations demonstrated that differences in the pyrolysis temperature of the precursors and heat transfer are crucial to the formation of the hollow nanostructure.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
February 2021
To explore the heterogeneity of spatial distribution and particle size distribution (PSD) in the main underlying surface soil in the source area of the Yangtze River, we used the fractal theory to describe the soil particle size distribution of alpine steppe and alpine meadow, and analyzed the difference of fractal dimension characteristics of soil of two different underlying surface and its relationship with soil particle composition. The results showed that soil particle size in the study area was mainly concentrated in 100-800 μm. The single fractal dimension () of alpine steppe soil was 2.
View Article and Find Full Text PDFCopper manganese composite (hopcalite) catalyst has been widely explored for low-temperature CO oxidation reactions. However, the previous reports on the stabilization of such composite catalysts have shown that they deactivated severely under moist conditions. Herein, we developed an α-MnO nanorod-supported copper oxide catalyst that is very active and stable for the conditions with or without moisture by the deposition precipitation (DP) method.
View Article and Find Full Text PDFJ Am Chem Soc
November 2019
The construction of stable active site in nanocatalysts is of great importance but is a challenge in heterogeneous catalysis. Unexpectedly, coordination-unsaturated and atomically dispersed copper species were constructed and stabilized in a sintered copper-ceria catalyst through air-calcination at 800 °C. This sintered copper-ceria catalyst showed a very high activity for CO oxidation with a CO consumption rate of 6100 μmol·g·s at 120 °C, which was at least 20 times that of other reported copper catalysts.
View Article and Find Full Text PDFExploring the state-of-the-art heterogeneous catalysts has been a general concern for sustainable and clean energy. Here, Pt-embedded CuO -CeO multicore-shell (Pt/CuO -CeO MS) composites are fabricated at room temperature via a one-pot and template-free procedure for catalyzing CO oxidation, a classical probe reaction, showing a volcano-shaped relationship between the composition and catalytic activity. We experimentally unravel that the Pt/CuO -CeO MS composites are derived from an interfacial autoredox process, where Pt nanoparticles (NPs) are in situ encapsulated by self-assembled ceria nanospheres with CuO clusters adhered through deposition/precipitation-calcination process.
View Article and Find Full Text PDFObjective: To explore the effects of Wnt5a and Wint7a on the differentiation of human embryonic stem cells (hESCs) into endometrium-like cells, and provide a basis for establishing endometrium-like cell models and a cell source for carrying out further endometrium-related experiments.
Methods: The hESCs established by our center were differentiated into endometrium-like cells in 4 different media including Wnt5a (Group A), Wnt7a (Group B), secreted frizzled related protein (sFRP, an inhibitor of Wnt signal pathway, Group C) and medium alone (Group D). In the differentiated terminal cells, the expressions of cytokeratin (CK) and vimentin were detected with immunofluorescence, and the mRNA levels of CK18, epithelial cell adhesion molecule (EPCAM), estrogen receptor (ER) and progesterone receptor (PR) were determined with RT-PCR.
The quality and safety of human embryonic stem cells (hESCs) in clinical application depend on gene stability. Two Chinese hESC lines, Zh1 and Zh21, were incubated over a long period. We observed and compared the gene stability in the passage numbers 20, 17 for Zh1 cell line and passage numbers 27, 60, 68 for Zh21 cell line.
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