LDH-derived catalysts for complete oxidation of volatile organic compounds

Clay Minerals ◽  
1999 ◽  
Vol 34 (1) ◽  
pp. 67-77 ◽  
Author(s):  
K. Bahranowski ◽  
E. Bielańska ◽  
R. Janik ◽  
T. Machej ◽  
E. M. Serwicka
Keyword(s):  
Catalytic Activity ◽  
Mixed Oxide ◽  
Copper Chromite ◽  
Oxide System ◽  
High Catalytic Activity ◽  
Commercial Catalyst ◽  
Volatile Organic ◽  
Double Hydroxides ◽  
Very High

AbstractThe Cu,Cr-, Zn,Cr- and Cu,Al-layered double hydroxides have been synthesized by the coprecipitation method and characterized by elemental analysis, PXRD, SEM/EDS and BET. The mixed oxide materials obtained upon calcination at 873 K show very high catalytic activity for the combustion of toluene and ethanol. The best sample is derived from the Cu,Cr-LDH precursor with a Cu:Cr ratio of 2, composed of copper oxide and copper chromite. This catalyst gave 50% conversion of toluene and ethanol at temperatures of 45 and 15 K lower, respectively, than the reference commercial catalyst. Catalytic tests with a mechanical mixture of CuO and CuCr2O4 demonstrate that the use of an LDH precursor is essential for optimum results. The importance of the simultaneous presence of both Cu and Cr, the influence of the Cu:Cr ratio on the catalytic activity and the role of the interface boundaries in the CuO-CuCr2O4 mixed oxide system are discussed.

Role of microporous Janus silica nanosheets in the assembly of ultra-small Ag nanoparticles with high catalytic activity

2021 ◽  
Vol 50 (1) ◽  
pp. 208-216
Author(s):  
Mengnan Yang ◽  
Zhaoli Yan ◽  
Tiantian Li ◽  
Bing Liu ◽  
Qiangshan Jing ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Ag Nanoparticles ◽  
High Catalytic Activity ◽  
Charged Surface ◽  
Highly Efficient ◽  
Surface Hydroxyls

Negatively charged surface hydroxyls and micropores of Janus silica nanosheets play a particular role in the highly efficient and dispersed assembly of ultra-small Ag nanoparticles with high catalytic activity.

scholarly journals Evaluation of a Catalyst Durability in Absence and Presence of Toluene Impurity: Case of the Material Co2Ni2Mg2Al2 Mixed Oxide Prepared by Hydrotalcite Route in Methane Dry Reforming to Produce Energy

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1362
Author(s):  
Carole Tanios ◽  
Cédric Gennequin ◽  
Madona Labaki ◽  
Haingomalala Lucette Tidahy ◽  
Antoine Aboukaïs ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Mixed Oxide ◽  
Active Sites ◽  
Dry Reforming ◽  
Dry Reforming Of Methane ◽  
Side Reactions ◽  
Commercial Catalyst ◽  
Catalytic Sites ◽  
Catalyst Durability ◽  
Catalytic Performances

Ni, Co, Mg, and Al mixed-oxide solids, synthesized via the hydrotalcite route, were investigated in previous works toward the dry reforming of methane for hydrogen production. The oxide Co2Ni2Mg2Al2 calcined at 800 °C, Co2Ni2Mg2Al2800, showed the highest catalytic activity in the studied series, which was ascribable to an interaction between Ni and Co, which is optimal for this Co/Ni ratio. In the present study, Co2Ni2Mg2Al2800 was compared to a commercial catalyst widely used in the industry, Ni(50%)/Al2O3, and showed better activity despite its lower number of active sites, as well as lower amounts of carbon on its surface, i.e. less deactivation. In addition to this, Co2Ni2Mg2Al2800 showed stability for 20 h under stream during the dry reforming of methane. This good durability is attributed to a periodic cycle of carbon deposition and removal as well as to the strong interaction between Ni and Co, preventing the deactivation of the catalyst. The evaluation of the catalytic performances in the presence of toluene, which is an impurity that exists in biogas, is also a part of this work. In the presence of toluene, the catalytic activity of Co2Ni2Mg2Al2800 decreases, and higher carbon formation on the catalyst surface is detected. Toluene adsorption on catalytic sites, side reactions performed by toluene, and the competition between toluene and methane in the reaction with carbon dioxide are the main reasons for such results.

Rapid and large-scale synthesis of Co3O4 octahedron particles with very high catalytic activity, good supercapacitance and unique magnetic properties

RSC Advances ◽  
2015 ◽  
Vol 5 (127) ◽  
pp. 104991-105002 ◽  
Author(s):  
Mahabubur Chowdhury ◽  
Oghenochuko Oputu ◽  
Mesfin Kebede ◽  
Franscious Cummings ◽  
Oscar Cespedes ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Catalytic Activity ◽  
Large Scale ◽  
High Catalytic Activity ◽  
Large Scale Synthesis ◽  
Very High

Octahedron Co3O4 particles with very high catalytic activity, good supercapacitance, and unique magnetic properties.

Effect of an Oxides Composite Support of Ce(Sm)O3-La(Sr)CrO3 on Pd-Ni Alloy for Decomposition Activity of CH4

2010 ◽  
Vol 65 ◽  
pp. 215-224
Author(s):  
Ichiro Yamanaka ◽  
Yuta Nabae ◽  
Takeo Ito
Keyword(s):  
Catalytic Activity ◽  
Spherical Shape ◽  
Open Circuit ◽  
Fiber Formation ◽  
Oxidation Catalysis ◽  
High Catalytic Activity ◽  
Composite Anode ◽  
Composite Support ◽  
Ni Alloy ◽  
Very High

A Pd-Ni/La(Sr)CrO3-Ce(Sm)O2 composite anode showed good performance for solid oxide fuel cell reactions with dry CH4. Compositions of Pd and Ni in the Pd-Ni/La(Sr)CrO3-Ce(Sm)O2 composite anode affected the electrochemical oxidation catalysis of dry CH4. The Pd and Ni ratios from 50:50 to 75:25 were suitable for the oxidation. The Pd-Ni/La(Sr)CrO3-Ce(Sm)O2 composite anode showed the high tolerance to the carbon deposition under closed and open circuit conditions. A Pd-Ni/Ce(Sm)O2 catalyst showed very low catalytic activity for decomposition of dry CH4. A Pd-Ni/SiO2 catalyst showed very high catalytic activity for the decomposition of dry CH4 and a large amount of deposited carbon formed. The Pd-Ni particles on SiO2 were quite multifaceted from TEM-EDS observation. On the other hand, the Pd-Ni particles on Ce(Sm)O2 support had a spherical shape and doping of Ce and Sm was confirmed. This nature should inhibit the formation of particular plane that is essential for the carbon fiber formation. The detail function of Ce(Sm)O2 and La(Sr)CrO3 supports was discussed.

Chitosan Based Nanocomposite Materials as Photocatalyst – A Review

2014 ◽  
Vol 781 ◽  
pp. 79-94 ◽  
Author(s):  
A. Nithya ◽  
Kandasamy Jothivenkatachalam ◽  
S. Prabhu ◽  
K. Jeganathan
Keyword(s):  
Catalytic Activity ◽  
Environmental Remediation ◽  
Low Cost ◽  
Nanocomposite Materials ◽  
Heterogeneous Photocatalysis ◽  
Organic Polymer ◽  
High Catalytic Activity ◽  
Environmental Application ◽  
Industrial Activities

Heterogeneous photocatalysis is a significant technology for environmental application. Moreover, immobilising an appropriate catalyst on the surface of a natural organic polymer presents a number of additional advantages including low-cost, high catalytic activity and extensive potential reuse for the application of pharmaceutical, biomedical and industrial activities. This review mainly focuses on the role of chitosan based material as photocatalyst on the environmental remediation.

scholarly journals Synthesis of FePcS–PMA–LDH Cointercalation Composite with Enhanced Visible Light Photo-Fenton Catalytic Activity for BPA Degradation at Circumneutral pH

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1951 ◽  
Author(s):  
Fenglian Huang ◽  
Shiqiang Tian ◽  
Yan Qi ◽  
Erping Li ◽  
Liangliang Zhou ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Bisphenol A ◽  
Visible Light ◽  
Layered Double Hydroxides ◽  
Electrochemical Impedance ◽  
Reaction System ◽  
High Catalytic Activity ◽  
Exchange Method ◽  
Double Hydroxides ◽  
Circumneutral Ph

(1) Background: Iron tetrasulfophthalocyanine with a large nonlinear optical coefficient, good stability, and high catalytic activity has aroused the attention of researchers in the field of photo-Fenton reaction. Further improvement of the visible light photo-Fenton catalytic activity under circumneutral pH conditions for their practical application is still of great importance. (2) Methods: In this paper, iron tetrasulfophthalocyanine (FePcS) and phosphomolybdic acid (PMA) cointercalated layered double hydroxides (LDH) were synthesized by the ion-exchange method. All samples were fully characterized by various techniques and the results showed that FePcS and PMA were successfully intercalated in layered double hydroxides and the resulted compound exhibited strong absorption in the visible light region. The cointercalation compound was tested as a heterogeneous catalyst for the visible light photo-Fenton degradation of bisphenol A (BPA) at circumneutral pH. (3) Results: The results showed that the degradation and total organic carbon removal efficiencies of bisphenol A were 100% and 69.2%, respectively. (4) Conclusions: The cyclic voltammetry and electrochemical impedance spectroscopy measurements demonstrated that the main contribution of PMA to the enhanced photo-Fenton activity of FePcS–PMA–LDH comes from the acceleration of electron transfer in the reaction system. Additionally, the possible reaction mechanism in the photo-Fenton system catalyzed by FePcS–PMA–LDH was also proposed.

Comparative Analysis of Catalytic Activity in Complex NiO-CuO-Fe2O3-Cr2O3 Oxide System of Different Production Technologies

2016 ◽  
Vol 870 ◽  
pp. 118-122 ◽  
Author(s):  
V.M. Chernyshev ◽  
N.P. Shabelskaya
Keyword(s):  
Catalytic Activity ◽  
Comparative Analysis ◽  
Phase Formation ◽  
Spinel Phase ◽  
Sewage Water ◽  
Oxide System ◽  
High Catalytic Activity ◽  
Organic Precursor ◽  
Organic Pigments ◽  
Synthesized Materials

The paper presents the comparative analysis of phase formation in NiO-CuO-Fe2O3-Cr2O3 system at salt decomposition reactions. Spinel phase formation is proven for each material. Synthesized materials are examined with X-ray phase analysis, low temperature nitrogen absorption, electronic microscope scanning. Highly dispersed spinel samples are proven to be obtained through synthesis at organic precursor presence. High catalytic activity of synthesized materials in the process of methyl orange oxidative destruction at hydrogen peroxide presence is determined. The fact is extremely useful for industrial sewage water treatment materials development for enterprises that employ organic pigments or colorants at their production process.

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