Evaluation of The Catalytic Activity of A High Surface Area, Regular, Porous Solid Formed From The Clusters of Clusters, MII4O[(CO)9Co3CCO2]6, M = Co, Zn

1992 ◽  
Vol 286 ◽  
Author(s):  
Wei Cen ◽  
Thomas P. Fehlner ◽  
Zbigniew Kalenik ◽  
Eduardo E. Wolf
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Catalytic Properties ◽  
High Surface ◽  
High Surface Area ◽  
Molecular Clusters ◽  
Porous Solid ◽  
Test Reaction ◽  
Solid Materials ◽  
Highly Porous

ABSTRACTThe discrete molecular clusters of clusters, M1140[(CO)9Co3CCO2]6, M = Co, Zn undergo thermolysis with the production of highly porous solid materials. Evaluation of the catalytic properties of these materials has been investigated using the hydrogenation of 1,3- butadiene as a test reaction. These experiments suggest it is the unique structure of the porous materials that is responsible for the high activities and the selectivities observed.

scholarly journals Peroxidase-Like Activity of Ferrihydrite and Hematite Nanoparticles for the Degradation of Methylene Blue

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Nicolaza Pariona ◽  
M. Herrera-Trejo ◽  
J. Oliva ◽  
A. I. Martinez
Keyword(s):  
Methylene Blue ◽  
Catalytic Activity ◽  
Surface Area ◽  
Catalytic Properties ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Process ◽  
Hematite Nanoparticles ◽  
High Crystallinity ◽  
Average Size

The peroxidase-like catalytic properties of 2-line ferrihydrite (2LFh) and hematite nanoparticles (NPs) for the degradation of methylene blue (MB) were studied. It is highlighted that the hematite NPs were prepared from the transformation of the metastable 2LFh NPs. It was found that the 2LFh NPs exhibited poor crystallinity with an average size of 5 nm, while the hematite NPs exhibited high crystallinity with an average size ofca. 100 nm. It was found that the total degradation of MB occurred for hematite NPs, while only a maximum degradation of 69% was possible for the 2LFh NPs. The Michaelis–Menten parameters indicated that the hematite NPs present higher catalytic activity than the 2LFh NPs at basic pH. It was found that the ordered surface of the hematite NPs has a stronger effect for the degradation of MB than its low surface area. It was concluded that the crystal planes of the hematite NPs affect the catalytic process more significantly than the high surface area of 2LFh NPs.

Spectroscopic Characterization of Mixed Titania-Silica Xerogel Catalysts

1999 ◽  
Vol 590 ◽  
Author(s):  
MA Holland ◽  
DM Pickup ◽  
G Mountjoy ◽  
SC Tsang ◽  
GW Wallidge ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Pore Structure ◽  
Surface Area ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Silica Xerogel ◽  
Test Reaction ◽  
Saxs Data ◽  
Surface Areas

ABSTRACTThe synthesis of high surface area (TiO2)0.18(SiO2)0.82xerogels has been achieved using the sol-gel route. Heptane washing was used before the drying stage to minimise capillary pressure and hence preserve pore structure and maximise the surface area. The as-prepared xerogels were tested for their catalytic activity using the epoxidation of cyclohexene with tert-butyl hydrogen peroxide (TBHP) as a test reaction. Surface areas up to 450 m2g-1 were achieved with excellent selectivities and reasonable percent conversions. SAXS data has identified that heptane washing during drying, in general, results in a preservation of the pore structure, and produces more effective catalysts with higher surface areas and larger pore diameters. Fr-IR spectroscopy has revealed that the catalytic activity is dependant upon the number of Si-O-Ti linkages, inferring intimate mixing of the precursors at the atomic level. XANES data reveals the presence of reversible 4/6-fold Ti sites that are thought to be ‘active’ catalytic sites. The most effective catalyst was produced with a calcination temperature of 500°C, and a heating rate of 5 °Cmin-l

Iodide-mediated templating synthesis of highly porous rhodium nanospheres for enhanced dehydrogenation of ammonia borane

2018 ◽  
Vol 6 (47) ◽  
pp. 24166-24174 ◽  
Author(s):  
Houbing Zou ◽  
Bo Jin ◽  
Runwei Wang ◽  
Yanbo Wu ◽  
Hengquan Yang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Ammonia Borane ◽  
Highly Porous ◽  
Templating Synthesis ◽  
Nanoporous Structures

A novel iodide-mediated templating strategy has been developed for preparing highly porous rhodium nanospheres (HPRhS) with exceptionally high surface area and controllable nanoporous structures, which showed a remarkable catalytic activity and stability in methanolytic dehydrogenation of ammonia borane.

scholarly journals Highly Porous Carbon Materials from Biomass by Chemical and Carbonization Method: A Comparison Study

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Wan Nor Roslam Wan Isahak ◽  
Mohamed Wahab Mahamed Hisham ◽  
Mohd Ambar Yarmo
Keyword(s):  
Sulfuric Acid ◽  
Thermal Behavior ◽  
Surface Area ◽  
Porous Carbon ◽  
High Surface ◽  
High Surface Area ◽  
Empty Fruit Bunches ◽  
Heating Treatment ◽  
Concentrated Sulfuric Acid ◽  
Highly Porous

Porous carbon obtained by dehydrating agent, concentrated sulfuric acid (H2SO4), from biomass containing high cellulose (filter paper (FP), bamboo waste, and empty fruit bunches (EFB)) shows very high surface area and better thermal behavior. At room temperature (without heating), treatment of H2SO4removed all the water molecules in the biomass and left the porous carbon without emitting any gaseous byproducts. Brunauer-Emmett-Teller (BET) surface analysis has shown that bamboo-based carbon has good properties with higher surface area (507.8 m2/g), micropore area (393.3 m2/g), and better thermal behavior (compared to FP and EFB) without any activation or treatment process. By acid treatment of biomass, it was shown that higher carbon composition obtained from FP (85.30%), bamboo (77.72%), and EFB (76.55%) is compared to carbon from carbonization process. Under optimal sulfuric acid (20 wt.%) uses, high carbon yield has been achieved for FP (47.85 wt.%), bamboo (62.4 wt.%), and EFB (55.4 wt.%).

scholarly journals A review on advanced nanofiber technology for membrane distillation

2019 ◽  
Vol 14 ◽  
pp. 155892501882490 ◽  
Author(s):  
Fatma Yalcinkaya
Keyword(s):  
Tissue Engineering ◽  
Surface Area ◽  
Wound Dressing ◽  
High Surface ◽  
High Surface Area ◽  
Membrane Distillation ◽  
Operating Parameters ◽  
Polymeric Nanofibers ◽  
Highly Porous ◽  
Comprehensive Study

The importance of the nanofiber webs increases rapidly due to their highly porous structure, narrow pore size, and distribution; specific surface area and compatibility with inorganics. Electrospinning has been introduced as one of the most efficient technique for the fabrication of polymeric nanofibers due to its ability to fabricate nanostructures with unique properties such as a high surface area and porosity. The process and the operating parameters affect the nanofiber fabrication and the application of nanofibers in various fields, such as sensors, tissue engineering, wound dressing, protective clothes, filtration, desalination, and distillation. In this review, a comprehensive study is presented on the parameters of electrospinning system including applications. More emphasis is given to the application of nanofibers in membrane distillation (MD). The research developments and the current situation of the nanofiber webs in MD are also discussed.

scholarly journals Metal Nanoparticles as Green Catalysts

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3602 ◽  
Author(s):  
Neel Narayan ◽  
Ashokkumar Meiyazhagan ◽  
Robert Vajtai
Keyword(s):  
Catalytic Activity ◽  
Composite Materials ◽  
Green Synthesis ◽  
Metal Nanoparticles ◽  
Surface Area ◽  
Significant Role ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Performance ◽  
Materials Development

Nanoparticles play a significant role in various fields ranging from electronics to composite materials development. Among them, metal nanoparticles have attracted much attention in recent decades due to their high surface area, selectivity, tunable morphologies, and remarkable catalytic activity. In this review, we discuss various possibilities for the synthesis of different metal nanoparticles; specifically, we address some of the green synthesis approaches. In the second part of the paper, we review the catalytic performance of the most commonly used metal nanoparticles and we explore a few roadblocks to the commercialization of the developed metal nanoparticles as efficient catalysts.

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