Chunzheng Wu

A soft-templated method to synthesize sintering-resistant Au–mesoporous-silica core–shell nanocatalysts with sub-5 nm single-cores

Nano-gold (sub-5 nm)@mesoporous-silica (m-SiO2) core-shell nanospheres with controlled size and core number were prepared via a soft-templated method. The single-core Au@m-SiO2 particles showed great sintering-resistance at 750 °C and kept high catalytic activity for CO oxidation after the treatment.

An artificial multiple triploid carp and its biological characteristics

The chromosomes of the artificial triploid carp consist of three complete genomes from Xingguo red carp (Cyprinus carpio), mirror carp (Cyprinus carpio) and red crucian carp (Carassius auratus). Starch and polyacrylamide gel analysis reveals that some SOD and s-MDH alleles of red crucian carp are undetectable in tissues of the artificial multiple triploid carp. It was found that the majority of oocytes of female artificial multiple triploid carp (XXX) developed to maturity, but spermatocytes of the male (XXY) developed abnormally and no spermatozoa were found. The external features of the triploid carp egg are quite different from those of normal diploid eggs. Sections of fertilized eggs reveal that the majority of eggs are polyspermous. Irradiated sperm was used to induce the gynogenesis of the artificial multiple triploid carp eggs. The eggs cleaved and developed normally, but the numbers of chromosomes of gastrular cells were variable, i.e., 50, 75, 100 and 150. This suggests that the behavior of the chromosomes in meiosis is polytypic, and some female nuclei of the eggs remain triploid after activation. All viable offspring of gynogenetic artificial multiple triploid carp are triploid and no segregation was found in their appearances, scale-covering type and body coloration.

Porosity effect on ZrO2 hollow shells and hydrothermal stability for catalytic steam reforming of methane

Hydrogen is an emerging energy source/carrier for oil refining and fuel cell applications. The development of an efficient and stable catalyst to produce hydrogen-rich gas is required for industrial application. The Ni@yolk-ZrO2 catalyst could be a potential solution to tackle the challenges in hydrogen production. The catalyst was characterized using a combination of XRD, TEM, AAS, TPR, BET, and XPS. In this study, the amount of micropores in ZrO2 hollow shells was demonstrated to influence the catalytic performance. Ni@yolk-ZrO2 catalysts were evaluated for 48 hours under steam reforming of methane and their porosity effect in ZrO2 hollow shells was identified. From the characterization of BET and catalytic evaluation, the physical information of the ZrO2 hollow shell was established, which affected the catalytic performance in steam reforming of methane. Furthermore, the results from XPS and TEM showed that Ni particles were controlled under a ZrO2 yolk–shell structure framework and showed the characteristic of moderately strong hydrothermal stability after the steam reforming test. The catalysts were studied at a GHSV of 50 400 mL gcat−1 h−1 and S/C = 2.5 at 750 °C and they remained stable with methane conversion more than 90% for 48 hours.

A novel and anti-agglomerating Ni@yolk–ZrO2 structure with sub-10 nm Ni core for high performance steam reforming of methane

Steam reforming of methane is a versatile technology for hydrogen production in oil refinery and fuel cell applications. Using natural gas is a promising method to produce rich-hydrogen gas. Ni@yolk–ZrO2 catalyst is used to study steam reforming of methane under various GHSVs, steam-to-carbon (S/C) ratio, and its recyclability. The catalyst was characterized using a combination of XRD, TEM, AAS, TPR, TPH, TGA, BET, XPS, and Raman techniques. The catalyst is evaluated on time stream and identify its anti-agglomeration property and coking mechanism. From the characterization of TEM and XPS establish the information of Ni particles mobility in the catalyst, which active metal particle size was controlled under the yolk–shell structure framework. Furthermore, the results from TGA, TPH, and Raman analysis of the used Ni@yolk–ZrO2 catalyst showed the characteristic of inhibiting formation of highly ordered carbon structure.