scholarly journals Structural Requirements for Chemoselective Ammonolysis of Ethylene Glycol to Ethanolamine over Supported Cobalt Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 736
Author(s):  
Xianchi Lei ◽  
Guoding Gu ◽  
Yafei Hu ◽  
Haoshang Wang ◽  
Zhaoxia Zhang ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Active Sites ◽  
Value Added ◽  
Cobalt Catalysts ◽  
Moderate Amount ◽  
Structural Requirements ◽  
Co Catalysts ◽  
Fast Development ◽  
Supported Cobalt Catalysts ◽  
Co Nanoparticles

Ethylene glycol is regarded as a promising C2 platform molecule due to the fast development of its production from sustainable biomass. This study inquired the structural requirements of Co-based catalysts for the liquid-phase ammonolysis of ethylene glycol to value-added ethanolamine. We showed that the rate and selectivity of ethylene glycol ammonolysis on γ-Al2O3-supported Co catalysts were strongly affected by the metal particle size within the range of 2–10 nm, among which Co nanoparticles of ~4 nm exhibited both the highest ethanolamine selectivity and the highest ammonolysis rate based on the total Co content. Doping of a moderate amount of Ag further promoted the catalytic activity without affecting the selectivity. Combined kinetic and infrared spectroscopic assessments unveiled that the addition of Ag significantly destabilized the adsorbed NH3 on the Co surface, which would otherwise be strongly bound to the active sites and inhibit the rate-determining dehydrogenation step of ethylene glycol.

scholarly journals Nanopowder-Supported Ultra-Low Content Co–Rh Bimetallic Catalysts for Hydroformylation of Monoformyltricyclodecenes to Value-Added Fine Chemicals

2018 ◽  
Vol 43 (3-4) ◽  
pp. 254-261
Author(s):  
Chengyang Li ◽  
Libo Zhang ◽  
Yubo Ma ◽  
Tianfu Wang
Keyword(s):  
Reaction Temperature ◽  
Bimetallic Catalysts ◽  
Active Sites ◽  
Value Added ◽  
Catalytic Performance ◽  
Fine Chemicals ◽  
Co Catalysts ◽  
Incipient Wetness ◽  
Incipient Wetness Method

The hydroformylation of monoformyltricyclodecenes (MFTD) to diformyltricyclodecanes (DFTD) was studied systematically. A series of 0.006 wt% Rh–0.006 wt% Co catalysts supported on commercially available nanopowders such as Al2O3, ZnO, TiO2 and CeO2 was prepared by the incipient wetness method and used to catalyse the hydroformylation of MFTD to DFTD. The 0.006 wt% Rh–0.006 wt% Co/ZnO catalyst showed the highest catalytic performance among the catalysts investigated, thus 41.8% DFTD yield with 100% DFTD selectivity could be achieved. This suggested that there may be a key role of the carrier on the catalytic performance in MFTD hydroformylation. Furthermore, the kinetic profiles for MFTD hydroformylation over the 0.006 wt% Rh–0.030 wt% Co/ZnO catalyst have been examined systematically to explore the effect of reaction temperature on the catalytic performance. These results collectively suggested that a particular reaction temperature might benefit MFTD hydroformylation. There may be some agglomeration of the active sites at higher reaction temperatures.

Mesoporous silica supported cobalt catalysts for gas phase hydrogenation of nitrobenzene: role of pore structure on stable catalytic performance

2018 ◽  
Vol 42 (19) ◽  
pp. 15714-15725 ◽  
Author(s):  
Murali Kondeboina ◽  
Siva Sankar Enumula ◽  
Venkata Ramesh Babu Gurram ◽  
Jyothi Yadagiri ◽  
David Raju Burri ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Pore Structure ◽  
Gas Phase ◽  
Catalytic Performance ◽  
Cobalt Catalysts ◽  
Co Catalysts ◽  
Pore Architecture ◽  
Supported Cobalt Catalysts

Mesoporous silica supported Co catalysts (Co/COK-12 and Co/SBA-16) are active for hydrogenation of nitrobenzene to aniline. The support pore architecture is decisive in maintaining stable catalytic performance.

Fischer–Tropsch synthesis over MOF-supported cobalt catalysts (Co@MIL-53(Al))

2016 ◽  
Vol 45 (30) ◽  
pp. 12006-12014 ◽  
Author(s):  
V. I. Isaeva ◽  
O. L. Eliseev ◽  
R. V. Kazantsev ◽  
V. V. Chernyshev ◽  
P. E. Davydov ◽  
...  
Keyword(s):  
Tropsch Synthesis ◽  
Cobalt Catalysts ◽  
Fischer Tropsch ◽  
Host Matrix ◽  
Fischer Tropsch Synthesis ◽  
Supported Cobalt Catalysts ◽  
Nanohybrid Materials ◽  
Co Nanoparticles

Novel nanohybrid materials were prepared by immobilizing Co nanoparticles on a microporous framework MIL-53(Al) as a porous host matrix.

scholarly journals Efficient Catalytic Conversion of Polysulfides by Biomimetic Design of “Branch-Leaf” Electrode for High-Energy Sodium–Sulfur Batteries

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Wenyan Du ◽  
Kangqi Shen ◽  
Yuruo Qi ◽  
Wei Gao ◽  
Mengli Tao ◽  
...  
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Electrochemical Reaction ◽  
Molecular Layer ◽  
Specific Capacity ◽  
High Energy ◽  
Reduction Reaction ◽  
Biomimetic Design ◽  
Co Nanoparticles ◽  
Sodium Sulfur

AbstractRechargeable room temperature sodium–sulfur (RT Na–S) batteries are seriously limited by low sulfur utilization and sluggish electrochemical reaction activity of polysulfide intermediates. Herein, a 3D “branch-leaf” biomimetic design proposed for high performance Na–S batteries, where the leaves constructed from Co nanoparticles on carbon nanofibers (CNF) are fully to expose the active sites of Co. The CNF network acts as conductive “branches” to ensure adequate electron and electrolyte supply for the Co leaves. As an effective electrocatalytic battery system, the 3D “branch-leaf” conductive network with abundant active sites and voids can effectively trap polysulfides and provide plentiful electron/ions pathways for electrochemical reaction. DFT calculation reveals that the Co nanoparticles can induce the formation of a unique Co–S–Na molecular layer on the Co surface, which can enable a fast reduction reaction of the polysulfides. Therefore, the prepared “branch-leaf” CNF-L@Co/S electrode exhibits a high initial specific capacity of 1201 mAh g−1 at 0.1 C and superior rate performance.

scholarly journals The Effect of Iron Impurities on Transition Metal Catalysts for the Oxygen Evolution Reaction in Alkaline Environment: Activity Mediators or Active Sites?

2020 ◽  
Author(s):  
Ioannis Spanos ◽  
Justus Masa ◽  
Aleksandar Zeradjanin ◽  
Robert Schlögl
Keyword(s):  
Transition Metal ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Active Sites ◽  
Water Electrolysis ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Alkaline Water Electrolysis ◽  
Co Catalysts ◽  
Model Transition

AbstractThere is an ongoing debate on elucidating the actual role of Fe impurities in alkaline water electrolysis, acting either as reactivity mediators or as co-catalysts through synergistic interaction with the main catalyst material. This perspective summarizes the most prominent oxygen evolution reaction (OER) mechanisms mostly for Ni-based oxides as model transition metal catalysts and highlights the effect of Fe incorporation on the catalyst surface in the form of impurities originating from the electrolyte or co-precipitated in the catalyst lattice, in modulating the OER reaction kinetics, mechanism and stability. Graphic Abstract

Promotion effects of Pd on tungsten carbide catalysts: physiochemical properties and cellulose conversion performance

RSC Advances ◽  
2016 ◽  
Vol 6 (90) ◽  
pp. 87756-87766 ◽  
Author(s):  
Glauco F. Leal ◽  
Silvia F. Moya ◽  
Debora M. Meira ◽  
Dean H. Barrett ◽  
Erico Teixeira-Neto ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Tungsten Carbide ◽  
Value Added ◽  
Aldol Reactions ◽  
One Pot ◽  
Cellulose Conversion ◽  
Physiochemical Properties ◽  
Conversion Performance

A multi-functional catalyst, which is able to perform both retro-aldol reactions followed by hydrogenation, is required to convert cellulose into value-added chemicals such as ethylene glycol (EG) in a one-pot reaction.

Fischer–Tropsch Synthesis on SiC-Supported Cobalt Catalysts

2013 ◽  
Vol 56 (9-10) ◽  
pp. 730-736 ◽  
Author(s):  
A. Lillebø ◽  
S. Håvik ◽  
E. A. Blekkan ◽  
A. Holmen
Keyword(s):  
Tropsch Synthesis ◽  
Cobalt Catalysts ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Supported Cobalt Catalysts

scholarly journals Exchange-traded products in Germany: development and substitution of exchange-traded funds, exchange-traded commodities and exchange-traded notes

Equilibrium ◽  
2018 ◽  
Vol 13 (4) ◽  
pp. 643-665
Author(s):  
Adam Marszk
Keyword(s):  
Value Added ◽  
Stock Exchanges ◽  
Exchange Traded Funds ◽  
Investment Funds ◽  
Market Shares ◽  
Time Period ◽  
Fast Development ◽  
Exchange Traded Notes ◽  
Insight Into ◽  
Total Market

Research background: Exchange-traded products (ETPs) are one of the most rapidly growing categories of financial products. Their fast development has been boosted by innovative features. Three main categories of ETPs are exchange-traded funds (ETFs), exchange-traded commodities (ETCs) and exchange-traded notes (ETNs). ETCs and ETNs remain least known, even though their number on some stock exchanges is high. In Europe, Germany is one of the largest and most active ETPs markets. ETCs and ETNs are debt instruments, in contrast with the most popular ETFs, which are equity securities. Therefore, they offer investors different advantages, but also expose them to other types of risks. Purpose of the article: The key aim of the article is to present the features of ETPs and to provide in-depth insight into the issues linked with the development of ETPs market in Germany, with the special emphasis on the ETCs and ETNs. Methods: In the main empirical part of the article, German ETPs market is analyzed using descriptive statistics and technological substitution framework (employed for the analysis of innovations in order to evaluate the changing market shares of, first, ETFs versus ETCs and ETNs, as well as, second, ETFs versus other types of investment funds). The period of the analysis is 2010–2016 in the former case and 2007–2016 in the latter. Findings & Value added: Share of ETPs other than ETFs in the total market in Germany remains low. Even though the market position of the leading products, i.e. ETFs, is still very strong, some substitution has been observed, especially after 2015. Predictions indicate that this trend will continue in the upcoming years. The results of the analysis of the investment funds’ market confirm the substitution between ETFs and traditional investment funds over 2007–2017, in particular in the first years of this time period.

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