Improving the efficiency of electrochemical CO2 reduction using immobilized manganese complexes

2015 ◽  
Vol 183 ◽  
pp. 147-160 ◽  
Author(s):  
James J. Walsh ◽  
Charlotte L. Smith ◽  
Gaia Neri ◽  
George F. S. Whitehead ◽  
Craig M. Robertson ◽  
...  
Keyword(s):  
Co2 Reduction ◽  
Manganese Complexes ◽  
Highly Active ◽  
Electrochemical Co2 Reduction ◽  
Nafion Membranes ◽  
Multi Walled Carbon Nanotubes ◽  
Acetonitrile Solutions ◽  
P Immobilization ◽  
Walled Carbon Nanotubes

Immobilization of [Mn(bpy)(CO)3Br], (1) and [Mn(bpy(tBu)2)(CO)3Br] (2, where (bpy(tBu)2) = 4,4′-di-tert-butyl-2,2′-bipyridine) in Nafion/multi-walled carbon nanotubes (MWCNT) on glassy carbon yielded highly active electrodes for the reduction of CO2 to CO in aqueous solutions at pH 7. Films incorporating 2 have significantly improved selectivity towards CO2, with CO : H2 ∼ 1 at −1.4 V vs. SCE, exceeding that for the previously reported 1/MWCNT/Nafion electrode. Furthermore, we report the synthesis and subsequent electrochemical characterization of two new substituted Mn(i) bipyridine complexes, [Mn(bpy(COOH)2)(CO)3Br] (3) and [Mn(bpy(OH)2)(CO)3Br] (4) (where (bpy(COOH)2) = 4,4′-di-carboxy-2,2′-bipyridine and (bpy(OH)2) = 4,4′-di-hydroxy-2,2′-bipyridine). Both 3 and 4 were found to have some activity towards CO2 in acetonitrile solutions; however once immobilized in Nafion membranes CO2 reduction was found to not occur at significant levels.

Electron Microscopy Characterization of Platinum Catalysts Supported on Multi-walled Carbon Nanotubes

2012 ◽  
Vol 18 (S2) ◽  
pp. 1316-1317
Author(s):  
M.J. Guinel ◽  
N. Brodusch ◽  
R. Gauvin ◽  
Y. Verde-Gomez ◽  
B. Escobar-Morales
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Platinum Catalysts ◽  
Multi Walled Carbon Nanotubes ◽  
Microscopy Characterization ◽  
Walled Carbon Nanotubes

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Surface and structural characterization of multi-walled carbon nanotubes following different oxidative treatments

Carbon ◽  
2011 ◽  
Vol 49 (1) ◽  
pp. 24-36 ◽  
Author(s):  
Kevin A. Wepasnick ◽  
Billy A. Smith ◽  
Kaitlin E. Schrote ◽  
Hannah K. Wilson ◽  
Stephen R. Diegelmann ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Structural Characterization ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

scholarly journals The Investigating the red phenol absorption by multi-walled carbon nanotubes

2020 ◽  
Vol 4 (1) ◽  
pp. First
Author(s):  
Huynh Anh Hoang ◽  
Huynh Quyen
Keyword(s):  
Carbon Nanotubes ◽  
Langmuir Isotherm ◽  
Full Potential ◽  
Liquefied Petroleum Gas ◽  
Research Results ◽  
Cvd Method ◽  
Multi Walled Carbon Nanotubes ◽  
Hydrocarbon Gas ◽  
Walled Carbon Nanotubes

Since the end of the 20th century, nanomaterials such as carbon nanotubes (CNTs) have been considered as one of the greatest achievements in the field of material science. Nowadays, further research on CNTs is still being conducted to unfold the full potential of this material. Generally, CNTs production methods have been extensively studied, specifically on CNTs synthesis route via liquefied hydrocarbon gas in the presence of a catalyst. From the synthesized material, further investigation including characterization and investigation of this nano size system’s effects on the physics, chemical, mechanical rules applied to macroscopic (bulk materials) and microscopic systems (atoms, molecules). In this present work, we demonstrated the research results of the synthesis of nano-carbon materials from a liquefied hydrocarbon gas (Liquefied Petroleum Gas: LPG) and its application to red phenol absorption in the liquid phase. CNTs used in this study were synthesized by chemical vapor deposition (CVD) method with Fe /ℽ-Al2O3 as the catalyst. The research results demonstrated that CNTs synthesized from LPG in this work were reported to be multi-walled tubes (MWCNTs: Multi-Walled Carbon Nanotubes) with physical characteristics including average internal and external diameters were of 6 nm and 17 nm, respectively. The measured specific surface suggested by BET data was 200 m2/g. The experimental study of red phenol adsorption by MWCNTs showed that the adsorption process followed both Freundlich and Langmuir isotherm adsorption models with the maximum monolayer adsorption capacity of 47.2 mg/g. The research results again showed that it was possible to synthesize MWCNTs from hydrocarbon gas sources via the CVD method by utilizing catalysts. Additionally, red phenol absorption via such material had shown to follow both Freundlich and Langmuir isotherm model, which allow further characterization of this material using Raman, EDX, SEM, TEM, BET, in order to extend the library database on the characterization of the reported synthesized material.

Characterization of Carbon Nanotube Growth via CVD Synthesis from a Liquid Precursor

2014 ◽  
Vol 23 (01n02) ◽  
pp. 1420001 ◽  
Author(s):  
Carol Jenkins ◽  
Melissa Cruz ◽  
Jen Depalma ◽  
Michael Conroy ◽  
Barbara Benardo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Conditions ◽  
Outer Diameter ◽  
Carrier Gas ◽  
Phase Precursor ◽  
Multi Walled Carbon Nanotubes ◽  
Carbon Nanotube Growth ◽  
Nanotube Growth ◽  
Walled Carbon Nanotubes

As novel theories and uses of carbon nanotubes (CNT) advance, it becomes increasingly important to characterize the methods of production. One such method of CNT production uses a liquid phase precursor (hydrocarbon with nanoparticle catalyst mix) that is injected into a tube furnace with a flowing carrier gas. The CNTs are grown in high purity and are collected on the surface of the quartz tube. The system allows for a number of variables to be tested such as growth temperatures, flow rate of the carrier gas, precursor injection rates and variations of precursor mix however, here only thermal effects are considered. Under thermal conditions ranging from 500 to 850°C, multi-walled carbon nanotubes (MWCNTs) are synthesized and characterized to determine inner and outer diameter as well as tube thickness.

Immobilization of Chaetomium erraticum dextranase (CED) by adsorption on carboxylated multi walled carbon nanotubes (c-MWCNT)

2021 ◽  
Author(s):  
Yakup Aslan ◽  
Barzan Ismael Ghafour
Keyword(s):  
Storage Conditions ◽  
Reducing Sugar ◽  
Solution Ph ◽  
Multi Walled Carbon Nanotubes ◽  
Activity Yield ◽  
Walled Carbon Nanotubes ◽  
Hydrolysis Of ◽  
Dextran Solution ◽  
Burk Plot

Abstract In this study, CED was immobilized onto c-MWCNT by adsorption. Optimization of immobilization conditions (immobilization buffer's pH and molarity, c-MWCNT amount, and immobilization time) was resulted in 100% immobilization yield and 114.13% activity yield. Further, characterization of FCED and ICED was also studied. After immobilization, the optimum pH shifted from 5.0 to 6.0, while the optimum temperature (55 °C) did not change. Furthermore, kinetic constants for FCED and ICED were also determined using the Lineweaver-Burk plot. The Km value for both FCED and ICED were 54.35 g / L, while Vmax values for FCED and ICED were 2.77 μmol reducing sugar / L.mg.min and 3.19 μmol reducing sugar / L.mg.min, respectively. Moreover, there was no reduction in the initial activity of ICED after 20 consecutive uses and 30 days of storage at optimal storage conditions. Finally, 17.15% and 17.53% of the dextran in 10% dextran solution (pH 6.0) were converted to reduced sugars (IMOs and Glucose) in 12 hours using FCED and ICED, respectively. Consequently, it can be concluded that ICED obtained in this study can be effectively used for industrial production of IMOs and for hydrolysis of dextran.

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