Hollow Mesoporous Organic Polymeric Nanobowls and Nanospheres: Shell Thickness and Mesopore-Dependent Catalytic Performance in Sulfonation, Immobilization of Organocatalyst, and Enantioselective Organocascade

2019 ◽  
Vol 58 (8) ◽  
pp. 2812-2823 ◽  
Author(s):  
Guangxin Xie ◽  
Shuai Wei ◽  
Li Zhang ◽  
Xuebing Ma
2019 ◽  
Vol 55 (4) ◽  
pp. 525-528 ◽  
Author(s):  
Lingshan Zhou ◽  
Binglu Deng ◽  
Zhongqing Jiang ◽  
Zhong-Jie Jiang

Core–shell Fe3O4@CoO NCs have been demonstrated to be efficient catalysts for ORR and OER. The specific core/shell interaction can be ascribed to the main reason leading to their high catalytic performance. The shell thickness has a great influence on the catalytic activities.


2016 ◽  
Vol 6 (21) ◽  
pp. 7698-7702 ◽  
Author(s):  
Fenglin Liao ◽  
Xin-Ping Wu ◽  
Jianwei Zheng ◽  
Meng-Jung Li ◽  
Ziyan Zeng ◽  
...  

A novel synthesis method of nano-Pd@Zn core–shell structures with controllable shell thickness showing remarkable catalytic performance in CO2hydrogenation.


2016 ◽  
Vol 6 (24) ◽  
pp. 8388-8391 ◽  
Author(s):  
A. Yazdi ◽  
F. Mercoçi ◽  
N. G. Bastús ◽  
I. Imaz ◽  
V. Puntes ◽  
...  

A series of ZIF-8 composites containing hollow Pt or Pd nanoparticles show that the size and the MOF shell thickness play a key role in the catalytic performance of this class of composites.


2019 ◽  
Vol 9 (3) ◽  
pp. 811-821 ◽  
Author(s):  
Zhao-Meng Wang ◽  
Li-Juan Liu ◽  
Bo Xiang ◽  
Yue Wang ◽  
Ya-Jing Lyu ◽  
...  

The catalytic activity decreases as –(SiO)3Mo(OH)(O) > –(SiO)2Mo(O)2 > –(O)4–MoO.


2020 ◽  
Vol 8 (35) ◽  
pp. 18207-18214
Author(s):  
Dongbo Jia ◽  
Lili Han ◽  
Ying Li ◽  
Wenjun He ◽  
Caichi Liu ◽  
...  

A novel, rational design for porous S-vacancy nickel sulfide catalysts with remarkable catalytic performance for alkaline HER.


Author(s):  
Arda Yıldırım ◽  
Ergin Öztürk

This study was conducted to determine the effect of cottonseed meal (CSM) incorporated into laying rations in place of soybean meal (SBM) at different ratios on yield traits. The birds began to lay at 6th week, 180 female and 45 male quails were used in laying period experiment. Birds were fed with rations containing 20% CP and 3000 Kcal/kg ME up to 20-week age (Laying period). CSM as a substitute, five different rations of the protein content (0, 30, 58, 86 and 100%) for SBM to basal diets based on corn-soybean meal were used. The results showed that there were no differences in terms of egg yield traits, cumulative feed consumptions and viabilities during the laying period. The highest dry shell rate and shell thickness were obtained from 5th group and 1st group, respectively. As a result, adding CSM instead of SBM in laying period were no significantly differences in terms of egg production and egg quality in laying period.


2019 ◽  
Author(s):  
M. Alexander Ardagh ◽  
Manish Shetty ◽  
Anatoliy Kuznetsov ◽  
Qi Zhang ◽  
Phillip Christopher ◽  
...  

Catalytic enhancement of chemical reactions via heterogeneous materials occurs through stabilization of transition states at designed active sites, but dramatically greater rate acceleration on that same active site is achieved when the surface intermediates oscillate in binding energy. The applied oscillation amplitude and frequency can accelerate reactions orders of magnitude above the catalytic rates of static systems, provided the active site dynamics are tuned to the natural frequencies of the surface chemistry. In this work, differences in the characteristics of parallel reactions are exploited via selective application of active site dynamics (0 < ΔU < 1.0 eV amplitude, 10<sup>-6</sup> < f < 10<sup>4</sup> Hz frequency) to control the extent of competing reactions occurring on the shared catalytic surface. Simulation of multiple parallel reaction systems with broad range of variation in chemical parameters revealed that parallel chemistries are highly tunable in selectivity between either pure product, even when specific products are not selectively produced under static conditions. Two mechanisms leading to dynamic selectivity control were identified: (i) surface thermodynamic control of one product species under strong binding conditions, or (ii) catalytic resonance of the kinetics of one reaction over the other. These dynamic parallel pathway control strategies applied to a host of chemical conditions indicate significant potential for improving the catalytic performance of many important industrial chemical reactions beyond their existing static performance.


2018 ◽  
Vol 70 (1) ◽  
Author(s):  
Serena J. Randolph ◽  
Alan D. Maccarone

Abstract Predation on bivalve mollusks by gastropod mollusks is common in coastal regions of the United States; however, few previous studies have examined whether drilling gastropods exhibit prey selection. In 2016, shells with small holes drilled by as many as two gastropod predators were collected at three sites separated by 30 km along the Texas Upper Gulf Coast on the Bolivar Peninsula (29° 40′N, 94° 90′W). The likeliest predators in these waters are the southern oyster drill (Stramonita haemastoma Linnaeus 1767) and the moon snail (Neverita duplicate Say 1822). Collected shells were identified to species and measurements were taken to examine statistical relationships between predators and prey species. These measurements included drill-hole diameter, shell thickness, drill-hole completeness, number of drill attempts, and collection site. Across the three locations, 17 different species of shells with drill holes were collected; of these, we focused on the ten most abundant species (n = 277 shells). The sample showed high variation in drill-hole diameter, shell thickness, and drill-hole completeness. Both the total number of holes and mean drill-hole diameter differed significantly among prey species (ANOVA, both P &lt; 0.0001). In addition, drill-hole diameter correlated directly with prey shell thickness (P &lt; 0.0001). Shells whose drill holes were complete were significantly thinner than shells with incomplete holes (P &lt; 0.0001). Mean prey shell thickness, mean drill-hole diameter, and mean number of drill holes all differed significantly by collection site (all P &lt; 0.0001). Ecological and morphological implications related to gastropod predation on mollusks are discussed.


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