Platinum loaded tin dioxide: a model system for unravelling the interplay between heterogeneous catalysis and gas sensing

2018 ◽  
Vol 6 (5) ◽  
pp. 2034-2046 ◽  
Author(s):  
David Degler ◽  
Sabrina A. Müller ◽  
Dmitry E. Doronkin ◽  
Di Wang ◽  
Jan-Dierk Grunwaldt ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Heterogeneous Catalysis ◽  
Structure Function ◽  
Tin Dioxide ◽  
Control Mechanism ◽  
Gas Sensing ◽  
Complex Structure ◽  
Model System

The presented work unravels the complex structure–function-relationships of Pt-loaded SnO2, namely the sensitization by a Fermi-control mechanism and relation of catalytic activity and gas sensing effect.

Deactivation of arenetitanium(II) bromoalane complexes in the cyclotrimerization of butadiene

1986 ◽  
Vol 51 (12) ◽  
pp. 2751-2759 ◽  
Author(s):  
Jindřich Poláček ◽  
Helena Antropiusová ◽  
Lidmila Petrusová ◽  
Karel Mach
Keyword(s):  
Catalytic Activity ◽  
Catalytic System ◽  
Model System ◽  
Highly Active ◽  
Catalytic Stability

The C6H6.Ti(II)(AlBr4)2 (Ib) catalyst deactivates during the butadiene cyclotrimerization to give a solid containing all titanium (mostly as TiBr3) and a mixture of AlBr3 and RAlBr2 compounds dissolved in benzene. The residual cationic catalytic activity of the deactivated Ib system is due to presence of AlBr3. In contrast to TiCl3, the deactivated Ib system and the model system TiBr3 + AlBr3 are not activated by the addition of EtAlCl2 in the presence of butadiene: the highly active benzenetitanium(II) system is re-constituted only after reduction of TiBr3 with Et3Al followed by the addition of EtAlCl2. The addition of Et2AlBr to Ib accelerates the deactivation of the system. Deactivation products of this system contain mainly Ti(II) species which forms benzenetitanium(II) catalytic system after addition of EtAlCl2. All the EtAlCl2 reactivated systems produce (Z, E, E)-1,5,9-cyclododecatriene with high catalytic stability and considerable selectivity (>90%). This behaviour points to the catalysis by benzenetitanium(II) chloroalane complexes containing only low amount of bromine atoms and ethyl groups.

scholarly journals Preparation and Gas Sensing Properties of PANI/SnO2 Hybrid Material

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1360
Author(s):  
Qiaohua Feng ◽  
Huanhuan Zhang ◽  
Yunbo Shi ◽  
Xiaoyu Yu ◽  
Guangdong Lan
Keyword(s):  
Hybrid Material ◽  
Room Temperature ◽  
Tin Dioxide ◽  
Gas Adsorption ◽  
Gas Sensing ◽  
Oxidative Polymerization ◽  
Environmental Pollutants ◽  
Decomposition Temperature ◽  
Benzene Vapor ◽  
Thermo Gravimetric Analyzer

A sensor operating at room temperature has low power consumption and is beneficial for the detection of environmental pollutants such as ammonia and benzene vapor. In this study, polyaniline (PANI) is made from aniline under acidic conditions by chemical oxidative polymerization and doped with tin dioxide (SnO2) at a specific percentage. The PANI/SnO2 hybrid material obtained is then ground at room temperature. The results of scanning electron microscopy show that the prepared powder comprises nanoscale particles and has good dispersibility, which is conducive to gas adsorption. The thermal decomposition temperature of the powder and its stability are measured using a differential thermo gravimetric analyzer. At 20 °C, the ammonia gas and benzene vapor gas sensing of the PANI/SnO2 hybrid material was tested at concentrations of between 1 and 7 ppm of ammonia and between 0.4 and 90 ppm of benzene vapor. The tests show that the response sensitivities to ammonia and benzene vapor are essentially linear. The sensing mechanisms of the PANI/SnO2 hybrid material to ammonia and benzene vapors were analyzed. The results demonstrate that doped SnO2 significantly affects the sensitivity, response time, and recovery time of the PANI material.

Enhanced gas sensing performance of tin dioxide-based nanoparticles for a wide range of concentrations of hydrogen gas

RSC Advances ◽  
2014 ◽  
Vol 4 (36) ◽  
pp. 18512 ◽  
Author(s):  
Pratanu Nag ◽  
Sanhita Majumdar ◽  
Ali Bumajdad ◽  
Parukuttyamma Sujatha Devi
Keyword(s):  
Tin Dioxide ◽  
Gas Sensing ◽  
Hydrogen Gas ◽  
Wide Range ◽  
Sensing Performance

Gas sensing properties of tin dioxide coated onto multi-walled carbon nanotubes

2006 ◽  
Vol 497 (1-2) ◽  
pp. 355-360 ◽  
Author(s):  
Yan-Li Liu ◽  
Hai-Feng Yang ◽  
Yu Yang ◽  
Zhi-Min Liu ◽  
Guo-Li Shen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Tin Dioxide ◽  
Gas Sensing ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Reduction in lignin peroxidase activity revealed by effects of lignin content in urea crosslinked starch under aerobic biodegradation in soil

BioResources ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1940-1948
Author(s):  
Zahid Majeed ◽  
Zainab Ajab ◽  
Qingjie Guan ◽  
Abdul Zahir Abbasi ◽  
Qaisar Mahmood ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Lignin Peroxidase ◽  
Enzyme Assay ◽  
Lignin Content ◽  
Complex Structure ◽  
Reaction Rates ◽  
Aerobic Biodegradation ◽  
Lignin Biodegradation ◽  
Research Findings ◽  
Biodegradation In Soil

This study characterized the lignin peroxidase (LiP) activity of soil via an enzyme assay to determine the reaction rates and activation energies for 5 wt%, 10 wt%, 15 wt%, and 20 wt% lignin loads in urea crosslinked starch biocomposites. The results revealed that a mixed mode of LiP inhibition occurred after the soil was mixed with these biocomposites with different loads of lignin. Loading of lignin at 5 wt% and 10 wt% lignin resulted in higher values of catalytic activity of LiP: -39.58 and 49.14 µM h-1 g-1 soil, respectively. In comparison, with higher loading of lignin at 15 wt% and 20 wt%, decreases in the catalytic activity of LiP were found and were 28.72 to 37.25 µM h-1 g-1 soil, respectively. The activation energy of LiP increased approximately 1.11- to 1.22-fold when 15 and 20 wt% of lignin was loaded in biocomposites. Research findings established the possibility of unfavorable binding of the LiP to lignin with an increase in the load of lignin, possibly due to the complex structure of intact lignin and presence of inhibitory biodegradation products of lignin accumulates during lignin biodegradation in biocomposites. It was concluded that higher lignin contents (15 wt% and 20 wt%) were effective in reducing the activity of the soil LiP. Hence, higher lignin content possibly protects against losses of lignin, while acting as a filler in the formulation of biocomposites.

The Effect of Sulfating Agent Nature on the Catalytic Activity Tin Dioxide Aerogel

2021 ◽  
Vol 66 (2) ◽  
pp. 288-293
Author(s):  
E. A. Straumal ◽  
L. L. Yurkova ◽  
A. E. Baranchikov ◽  
V. P. Kazachenko ◽  
T. N. Fursova ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Tin Dioxide ◽  
Sulfating Agent

CHLORINE GAS SENSING OF SnO2 NANOCLUSTERS AS A FUNCTION OF TEMPERATURE: A DFT STUDY

2019 ◽  
Vol 26 (04) ◽  
pp. 1850172
Author(s):  
MUDAR AHMED ABDULSATTAR ◽  
ADEEBH L. RESNE ◽  
SHROK ABDULLAH ◽  
RIYADH J. MOHAMMED ◽  
NOON KADHUM ALARED ◽  
...  
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Density Functional ◽  
Tin Dioxide ◽  
Energy Gap ◽  
Gas Sensing ◽  
Free Energy Calculations ◽  
Measured Temperature ◽  
Chlorine Molecule ◽  
Chlorine Gas

Density functional theory combined with Gibbs free energy calculations is used to study the sensing behavior of tin dioxide (SnO[Formula: see text] clusters towards chlorine gas molecules. Studied SnO2 clusters’ results show the known property of tin dioxide being an oxygen-deficient semiconductor with the preferred stoichiometry SnO[Formula: see text]. The kind of reactions that result in sensing Cl2 molecules is investigated. These include oxygen replacement, chlorine molecule dissociation and van der Waals attachment. Oxygen replacement shows an increase in energy gap which is the case experimentally. Optimum sensing operating temperature towards Cl2 molecules that results from the intersection of the highest SnO2 adsorption and desorption Gibbs free energy lines is at 275∘C in agreement with the experimentally measured temperature of 260∘C.

scholarly journals Imidazolium functionalized carbon nanotubes for the synthesis of cyclic carbonates: reducing the gap between homogeneous and heterogeneous catalysis

2016 ◽  
Vol 6 (24) ◽  
pp. 8418-8427 ◽  
Author(s):  
M. Buaki-Sogó ◽  
A. Vivian ◽  
L. A. Bivona ◽  
H. García ◽  
M. Gruttadauria ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Catalytic Activity ◽  
Heterogeneous Catalysis ◽  
Single Walled Carbon Nanotubes ◽  
The Novel ◽  
Cyclic Carbonates ◽  
Functionalized Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Novel Materials ◽  
Walled Carbon Nanotubes

Single walled carbon nanotubes were functionalized with imidazolium based salts and successfully used as catalysts for the conversion of CO2. The novel materials displayed excellent catalytic activity.

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