Effect of noble metals on selective detection of liquid petroleum gas by SnO2

1998 ◽  
Vol 13 (7) ◽  
pp. 1780-1785 ◽  
Author(s):  
A. R. Phani ◽  
M. Pelino
Keyword(s):  
Photoelectron Spectroscopy ◽  
Noble Metals ◽  
Electrical Response ◽  
Chemical Species ◽  
Gaseous Mixture ◽  
High Sensitivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Liquid Petroleum Gas ◽  
Spectroscopy Studies

The present investigation deals with the electrical response of doped SnO2 to improve the selectivity for liquid petroleum gas (LPG) in the presence of CO and CH4, by utilizing noble metal sensitizers such as Pd, Pt, and Rh. SnO2 with the addition of Pd (1.5 wt. %) or Pt (1.5 wt. %) sintered at 800 °C which have shown high sensitivity toward LPG with no cross interference of CO and CH4 at an operating temperature of 350 °C. The results suggest the possibility of utilizing the sensor for the detection of this hydrocarbon gaseous mixture. X-ray diffraction studies have been carried out to evaluate the crystallite size as a function of sintering temperature; x-ray photoelectron spectroscopy studies have been carried out to define the possible chemical species involved in the gas-solid interaction and the sensitivity enhancing mechanism of the SnO2/Pd sensor element toward LPG.

Effect of Noble Metals on Selective Detection of LPG Based on SnO2

1996 ◽  
Vol 459 ◽  
Author(s):  
A. Ratna Phani ◽  
M. Pelino
Keyword(s):  
Photoelectron Spectroscopy ◽  
Noble Metals ◽  
Electrical Response ◽  
Base Material ◽  
High Sensitivity ◽  
Precipitation Method ◽  
X Ray ◽  
Spectroscopy Studies ◽  
Metal Doped ◽  
Co Precipitation

ABSTRACTThe present investigation deals with the electrical response of noble metal doped SnO2 to improve the selectivity for Liquid Petroleum Gas (LPG) in the presence of CO and CH4. Addition of small amounts of nobel metals (Pd, Pt and Rh) to the base material SnO2 is carried out by co-precipitation method. X-ray diffraction and X-ray photoelectron spectroscopy studies are carried out to find out the crystalline phase and chemical composition of the SnO2. The sensor element has been tested for cross selectivity to reducing gases by measuring sensitivity versus sintering temperatures and sensitivity versus operating temperatures. The sensor elements with the composition of Pd (1.5 wt%) andPt (1.5 wt%) in the base material SnO2 sintered at 800°C showed high sensitivity towards LPG at an operating temperature of 350°C suggestingthe possibility to utilize the sensor for the detection of LPG.

scholarly journals Biodiesel Production on Monometallic Pt, Pd, Ru, and Ag Catalysts Supported on Natural Zeolite

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 48
Author(s):  
Pawel Mierczynski ◽  
Magdalena Mosińska ◽  
Lukasz Szkudlarek ◽  
Karolina Chalupka ◽  
Misa Tatsuzawa ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Natural Zeolite ◽  
Noble Metals ◽  
Methyl Esters ◽  
Physicochemical Characteristics ◽  
Biodiesel Production ◽  
X Ray Diffraction ◽  
X Ray ◽  
Yield Values ◽  
Temperature Programmed

Biodiesel production from rapeseed oil and methanol via transesterification reaction facilitated by various monometallic catalyst supported on natural zeolite (NZ) was investigated. The physicochemical characteristics of the synthesized catalysts were studied by X-ray diffraction (XRD), Brunauer–Emmett–Teller method (BET), temperature-programmed-reduction in hydrogen (H2-TPR), temperature-programmed-desorption of ammonia (NH3-TPD), Scanning Electron Microscope equipped with EDX detector (SEM-EDS), and X-ray photoelectron spectroscopy (XPS) methods. The highest activity and methyl ester yields were obtained for the Pt/NZ catalyst. This catalyst showed the highest triglycerides conversion of 98.9% and fatty acids methyl esters yields of 94.6%. The activity results also confirmed the high activity of the carrier material (NZ) itself in the investigated reaction. Support material exhibited 90.5% of TG conversion and the Fatty Acid Methyl Esters yield (FAME) of 67.2%. Introduction of noble metals improves the TG conversion and FAME yield values. Increasing of the metal loading from 0.5 to 2 wt.% improves the reactivity properties of the investigated catalysts.

Preparation and Characterization of γ-Fe2O3-ZnFe2O4 Composite Nanoparticles

2013 ◽  
Vol 873 ◽  
pp. 152-157
Author(s):  
Long Long Chen ◽  
Jun Ming Li ◽  
Xiao Min Gong ◽  
Jian Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Species ◽  
Composite Nanoparticles ◽  
X Ray Diffraction ◽  
Ferrite Core ◽  
Phase Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Chemically Induced

Using a chemically induced transition in an FeCl2 solution, γ-Fe2O3 nanoparticles can be prepared from an amorphous precursor composed of FeOOH and Mg (OH)2. Surface modification by adding ZnCl2 during liquid-phase synthesis was attempted. The magnetization, morphology, crystal structure, and chemical species of as-prepared samples were characterized by vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray energy-dispersive spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). The experimental results showed that the surface of the γ-Fe2O3 nanoparticles can be modified by adding ZnCl2 to form composite nanoparticles with a γ-Fe2O3/ZnFe2O4 ferrite core coated with Zn (OH)2 and absorbed FeCl36H2O; this modification can be enhanced by additional NaOH.

scholarly journals Термодинамические свойства оксипентафторида ванадия (IV), (NH-=SUB=-4-=/SUB=-)-=SUB=-3-=/SUB=-VOF-=SUB=-5-=/SUB=-

2020 ◽  
Vol 62 (7) ◽  
pp. 1123
Author(s):  
Е.В. Богданов ◽  
Е.И. Погорельцев ◽  
А.В. Карташев ◽  
М.В. Горев ◽  
М.С. Молокеев ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Photoelectron Spectroscopy ◽  
Single Phase ◽  
Dielectric Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Limits Of Stability ◽  
Three Phase ◽  
Temperature Dependences ◽  
Spectroscopy Studies

Abstract The (NH_4)_3VOF_5 crystals have been synthesized and their homogeneity and single-phase structure has been established by the X-ray diffraction, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy studies. The investigations of the temperature dependences of specific heat, entropy, strain, and pressure susceptibility show the occurrence of three phase transitions caused by the structural transformations in the (NH_4)_3VOF_5 crystals. The T – p phase diagram shows the temperature limits of stability of the crystalline phases implemented in (NH_4)_3VOF_5. The optical and dielectric studies disclose the ferroelastic nature of the phase transitions. An analysis of the experimental data together with the data on the isostructural (NH_4)_3VO_2F_4 crystal makes it possible to distinguish the physical properties of oxyfluorides containing vanadium of different valences (IV and V).

Green preparation of carbon dots for Hg2+ detection and cell imaging

2020 ◽  
Vol 10 (11) ◽  
pp. 1777-1787
Author(s):  
Yadian Xie ◽  
Shanshan Wang ◽  
Ning Fu ◽  
Yan Yang ◽  
Xingliang Liu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Dots ◽  
High Sensitivity ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon And Nitrogen ◽  
Transmission Electron ◽  
Sensitivity And Selectivity ◽  
Ft Ir

Carbon dots (CDs) also nitrogen-doped CDs (N-CDs) were produced by green hydrothermal synthesis using Pea and ethanediamine as the carbon and nitrogen source, separately. Transmission electron microscopy (TEM) images displayed that the prepared CDs and N-CDs were well dispersed, had a spherical morphology. X-ray diffraction (XRD) figures of CDs and N-CDs presented a graphitic amorphous structure. Fourier transform infrared spectroscopy (FT-IR) verified that CDs and N-CDs carried many different hydrophilic groups (for example hydroxyl, carboxyl/carbonyl, amide, amino groups) on the surface, X-ray photoelectron spectroscopy (XPS) together verified this result. However, the optical properties and fluorescence quantum yield for N-CDs were obviously superior to those of CDs. Furthermore, the prepared N-CDs displayed outstanding advantages including low toxicity, satisfactory biocompatibility, and excellent chemical stability. More prominently, the prepared N-CDs could detect Hg2+ ions with high sensitivity and selectivity in both water samples and HeLa cells.

Synchrotron X-ray diffraction and X-ray photoelectron spectroscopy studies of NaAlH4 containing Ti–Zr hydride additives

2009 ◽  
Vol 486 (1-2) ◽  
pp. 436-441 ◽  
Author(s):  
Chubin Wan ◽  
Xin Ju ◽  
Ying Qi ◽  
Shumao Wang ◽  
Xiaopeng Liu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spectroscopy Studies
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