Spatiotemporal Heterogeneity of Temperature and Catalytic Activation within Individual Catalyst Particles.

Temperature is a critical parameter in chemical conversion, significantly affecting the reaction kinetics and thermodynamics. Measuring temperature inside catalyst particles of industrial interest (∼micrometers to millimeters), which is crucial for understanding the evolution of chemical dynamics at catalytic active sites during reaction and advancing catalyst designs, however, remains a big challenge. Here, we propose an approach combining two-photon confocal microscopy and state-of-the-art upconversion luminescence (UL) imaging to measure the spatiotemporal-resolved temperature within individual catalyst particles in the industrially significant methanol-to-hydrocarbons reaction. Specifically, catalyst particles containing zeolites and functional nanothermometers were fabricated using microfluidic chips. Our experimental results directly demonstrate that the zeolite density and particle size can alter the temperature distribution within a single catalyst particle. Importantly, the observed temperature heterogeneity plays a decisive role in the activation of the reaction intermediate and the utilization of active sites. We expect that this work opens a venue for unveiling the reaction mechanism and kinetics within industrial catalyst particles by considering temperature heterogeneity.

Manipulating interstitial carbon atoms in the nickel octahedral site for highly efficient hydrogenation of alkyne.

Light elements in the interstitial site of transition metals have strong influence on heterogeneous catalysis via either expression of surface structures or even direct participation into reaction. Interstitial atoms are generally metastable with a strong environmental dependence, setting up giant challenges in controlling of heterogeneous catalysis. Herein, we show that the desired carbon atoms can be manipulated within nickel (Ni) lattice for improving the selectivity in acetylene hydrogenation reaction. The radius of octahedral space of Ni is expanded from 0.517 to 0.524 Å via formation of Ni3Zn, affording the dissociated carbon atoms to readily dissolve and diffuse at mild temperatures. Such incorporated carbon atoms coordinate with the surrounding Ni atoms for generation of Ni3ZnC0.7 and thereof inhibit the formation of subsurface hydrogen structures. Thus, the selectivity and stability are dramatically improved, as it enables suppressing the pathway of ethylene hydrogenation and restraining the accumulation of carbonaceous species on surface.

Effects of ß-conglycinin on growth performance, immunoglobulins and intestinal mucosal morphology in piglets.

One of the main causes of allergic reactions in young animals is ß-conglycinin, an antigenic glycoprotein found in soya beans. Therefore, the objective of the study was to investigate the effects of a prior immunisation with ß-conglycinin on growth performance, serum immunoglobulin levels and intestinal histology in piglets. Forty piglets (7 d of age) were randomly divided into four groups of ten piglets each. Piglets of Groups Im and Im+S were immunised twice by hypodermic injection with ß-conglycinin at 500 µg/kg body weight (BW) at day 7 and 21 of age. At day 23, Groups Im+S and S were intramuscularly injected with 5000 µg ß-conglycinin per kg BW. The piglets of Group C received a physiological saline solution by hypodermic injection. All piglets were weaned at the age of 23 d and blood samples were taken on days 7, 21 and 35. At the end of the trial, five piglets per group were slaughtered and the intestine was collected for evaluating mucosal histology. Compared to Group C, in Group S the average daily gain (ADG), feed intake and gain:feed ratio were decreased (p < 0.01), and serum levels of IgG and IgE were increased (p < 0.01). Furthermore, in this group the structure of duodenal and jejunal mucosa was severely damaged. But in Groups Im and Im+S the ADG was increased (p < 0.05), serum IgE levels were decreased (p < 0.01) and the intestinal mucosa was not damaged. The results suggest that prior immunisation with ß-conglycinin can increase ADG and serum IgG levels and decrease serum IgE levels. Therefore, this method is also potentially able to protect the structural integrity of the intestinal mucosal epithelia and alleviate allergic reactions in piglets.

[Influence of repeated platelet donation on megakaryopoiesis in donors].

To explore influence of platelet donation on donor's megakaryocytopoiesis, platelet counts and plasma concentrations of thrombopoietin (TPO), interleukin-3 (IL-3), IL-6 and nitric oxide (NO) were determined in 42 frequent platelet donors (undergoing plateletpheresis more than once a month for 24 months and their mean platelet yield of collection was 2.5 x 10(11)), in 62 limited platelet donors (undergoing plateletpheresis less than once a month for 24 months) after a donation-free period of > 5 weeks and in 40 whole blood donors who never undergoing plateletpheresis after a donation-free period of > 6 months. The results showed that the TPO levels was significantly lower in frequent platelet donors than in limited platelet donors (P < 0.01) and whole blood donors (P < 0.01). There were no significant differences between three groups in platelet counts, IL-3, IL-6 and NO. These findings suggest that the number of megakarocytes significantly increased in frequent platelet donors.