scholarly journals Photocatalytic Reduction of CO2 to Methanol Using a Copper-Zirconia Imidazolate Framework

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 346
Author(s):  
Sonam Goyal ◽  
Maizatul Shima Shaharun ◽  
Ganaga Suriya Jayabal ◽  
Chong Fai Kait ◽  
Bawadi Abdullah ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalyst Support ◽  
Oxidation Potential ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Optimum Parameters ◽  
Reduction Of Co2 ◽  
Enhanced Yield

A set of novel photocatalysts, i.e., copper-zirconia imidazolate (CuZrIm) frameworks, were synthesized using different zirconia molar ratios (i.e., 0.5, 1, and 1.5 mmol). The photoreduction process of CO2 to methanol in a continuous-flow stirred photoreactor at pressure and temperature of 1 atm and 25 °C, respectively, was studied. The physicochemical properties of the synthesized catalysts were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The highest methanol activity of 818.59 µmol/L.g was recorded when the CuZrIm1 catalyst with Cu/Zr/Im/NH4OH molar ratio of 2:1:4:2 (mmol/mmol/mmol/M) was employed. The enhanced yield is attributed to the presence of Cu2+ oxidation state and the uniformly dispersed active metals. The response surface methodology (RSM) was used to optimize the reaction parameters. The predicted results agreed well with the experimental ones with the correlation coefficient (R2) of 0.99. The optimization results showed that the highest methanol activity of 1054 µmol/L.g was recorded when the optimum parameters were employed, i.e., stirring rate (540 rpm), intensity of light (275 W/m2) and photocatalyst loading (1.3 g/L). The redox potential value for the CuZrIm1 shows that the reduction potential is −1.70 V and the oxidation potential is +1.28 V for the photoreduction of CO2 to methanol. The current work has established the potential utilization of the imidazolate framework as catalyst support for the photoreduction of CO2 to methanol.

Cathode Material Li [Li0.2 Mn0.44Ni0.18Co0.18]O2 Synthesized by Molten Salt Method

2013 ◽  
Vol 690-693 ◽  
pp. 981-984
Author(s):  
Guang Xin Fan ◽  
Hui Lian Li ◽  
Shu Pu Dai ◽  
Chuan Xiang Zhang ◽  
Xue Mao Guan ◽  
...  
Keyword(s):  
Molten Salt ◽  
Specific Area ◽  
Constant Current ◽  
Molar Ratio ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Structures And Properties ◽  
Constant Current Charge

In this paper, LiOH·H2O and Li2CO3, which were widely used in industry and (Mn0.533Co0.233Ni0.233) (OH)2prepared by ourselves selected as starting materials, series materials of lithium-rich layered material Li [Li0.2Mn0.44Ni0.18Co0.18]O2were obtained by a molten salt method. Their structures and properties of the materials were investigated by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and constant current charge/discharge methods. The effects of different LiOH and Li2CO3molar ratios on the Li [Li0.2Mn0.44Ni0.18Co0.18]O2structures and properties were characterized. The results of the experiments indicate that The structures of the material such as crystal structure, the specific area, particle size distribution, tap densities were controlled by adjusting the proportion of the two lithium sources. Forthermore , when the molar ratio of LiOH and Li2CO3was 3:7, the maximum discharge capacity (214.77 mAhg-1) of the cathode was obtained.

Synthesis, Characterization and Photocatalytic Activity of Nb-Doped TiO2 Nanoparticles

2012 ◽  
Vol 455-456 ◽  
pp. 110-114 ◽  
Author(s):  
Xuan Dong Li ◽  
Xi Jiang Han ◽  
Wen Ying Wang ◽  
Xiao Hong Liu ◽  
Yan Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Doped Tio2 ◽  
X Ray ◽  
Vis Spectroscopy

Nb-doped TiO2 powders with different concentrations of Nb have been synthesized by a sol-gel method and characterized by a series of technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The photocatalytic activity of Nb-doped TiO2 is evaluated by degradation efficiency of methyl orange in aqueous solution. The results indicate that the photocatalytic activity of Nb-doped TiO2 synthesized with a Nb/Ti molar ratio of 5% is higher than that of TiO2 under the visible light.

Stoichiometric Controlling of Spark Plasma Sintered Boron-Carbon Ceramics

2009 ◽  
Vol 66 ◽  
pp. 25-28 ◽  
Author(s):  
Song Zhang ◽  
Chuan Bin Wang ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Measurement Data ◽  
Atomic Ratio ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Carbon Ceramic ◽  
Boron Carbon

A group of boron-carbon ceramic material was in-situ synthesized and densified simultaneously via Spark Plasma Sintering (SPS) technique from carbon and boron element powders with different molar ratio. The phase structures of samples with different B/C molar ratio were characterized by X-ray Diffraction (XRD). The B/C atomic ratio of the sintered materials was calculated from X-ray photoelectron spectroscopy (XPS) measurement data. Meanwhile, the chemical analysis (CA) method had also been taken to verify the B/C atomic ratio. Finally, the experience equation had been obtained to control the B/C atomic ratio of sintered samples.

scholarly journals Structural, Surface Morphology and Optical Properties of ZnS Films by Chemical Bath Deposition at Various Zn/S Molar Ratios

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Fei-Peng Yu ◽  
Sin-Liang Ou ◽  
Pin-Chuan Yao ◽  
Bing-Rui Wu ◽  
Dong-Sing Wuu
Keyword(s):  
Chemical Bath Deposition ◽  
Photoelectron Spectroscopy ◽  
Visible Region ◽  
Film Surface ◽  
Optical Transmittance ◽  
Molar Ratio ◽  
Infrared Spectrometry ◽  
X Ray ◽  
Molar Ratios ◽  
Zns Films

In this study, ZnS thin films were prepared on glass substrates by chemical bath deposition at various Zn/S molar ratios from 1/50 to 1/150. The effects of Zn/S molar ratio in precursor on the characteristics of ZnS films were demonstrated by X-ray diffraction, scanning electron microscopy, optical transmittance, X-ray photoelectron spectroscopy, and Fourier transform infrared spectrometry. It was found that more voids were formed in the ZnS film prepared using the precursor with Zn/S molar ratio of 1/50, and the other ZnS films showed the denser structure as the molar ratio was decreased from 1/75 to 1/150. From the analyses of chemical bonding states, the ZnS phase was indeed formed in these films. Moreover, the ZnO and Zn(OH)2also appeared due to the water absorption on film surface during deposition. This would be helpful to the junction in cell device. With changing the Zn/S molar ratio from 1/75 to 1/150, the ZnS films demonstrate high transmittance of 75–88% in the visible region, indicating the films are potentially useful in photovoltaic applications.

scholarly journals Liquid petroleum gas sensing performance enhanced by CuO modification of nanocrystalline ZnO-TiO2

2016 ◽  
Vol 34 (3) ◽  
pp. 571-581
Author(s):  
R.B. Pedhekar ◽  
F.C. Raghuwanshi ◽  
V.D. Kapse
Keyword(s):  
Thick Film ◽  
Gas Sensing ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Transmission Electron ◽  
Liquid Petroleum Gas ◽  
Synthesized Materials ◽  
Sensing Characteristics

AbstractNanocrystalline ZnO-TiO2 (with molar ratios 9:1, 7:3, 1:1, 3:7 and 1:9) were successfully synthesized by hydrothermal method. Synthesized materials were examined with the help of X-ray diffraction and transmission electron microscope. Liquid petroleum gas sensing characteristics of the ZnO-TiO2 films were investigated at different operating temperatures. The ZnO-TiO2 thick film (with 1:1 molar ratio) exhibited good response toward liquid petroleum gas as compared to other investigated compositions. Further, liquid petroleum gas sensing characteristics of CuO modified ZnO-TiO2 thick films were investigated. 0.2 M CuO modified ZnO-TiO2 thick film exhibited excellent liquid petroleum gas sensing characteristics such as higher response (~ 1637.49 at 185 °C) with quick response time (~30 s), low recovery time (~70 s), excellent repeatability and stability at low operating temperature.

scholarly journals Synthesis of Layered Octadecyltrimethylammonium-Templated Aluminosilicate and its Use as a Thickening Agentfor Lubricating Grease

2021 ◽  
Author(s):  
Lukun Han ◽  
Wenxing Niu ◽  
Xinrui Zhao ◽  
Hong Xu ◽  
Jinxiang Dong
Keyword(s):  
Molar Ratio ◽  
Wear Property ◽  
X Ray Diffraction ◽  
Lubricating Grease ◽  
X Ray ◽  
Molar Ratios ◽  
Simple Preparation ◽  
Dropping Point ◽  
27Al Mas Nmr ◽  
Aluminum Silicon

Abstract We describe herein the use of octadecyltrimethylammonium-templated aluminosilicate (designated as LS) as a thickener to induce gelation. LS samples with different aluminum/silicon molar ratios (Al/Si = 0, 0.05, 0.10, 0.15, 0.20) were synthesized hydrothermally and characterized by X-ray diffraction analysis, 27Al MAS NMR spectra, elemental analysis, and scanning electron microscopy. The aluminum/silicon molar ratio was shown to be an important factor affecting the rheological properties of LS gels. With increasing Al/Si molar ratio, the viscoelasticity and structural strength of LS gel were enhanced, the dropping point increased, and the amount of oil separation decreased. LS(0.20) gel exhibited superior relative elastic character. The strength of the LS(0.20) gel was also enhanced with increasing LS(0.20) content. In SRV tests, LS(0.20) gel with different contents showed good performance in terms of load-bearing ability and anti-wear property, indicating that LS was strongly adhered on the friction surface, and thereby promoted lubrication. Owing to simple preparation, the promising rheological and tribological properties, LS gel hold great potential application in lubricating grease.

scholarly journals CO2 Methanation of Biogas over 20 wt% Ni-Mg-Al Catalyst: on the Effect of N2, CH4, and O2 on CO2 Conversion Rate

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1201
Author(s):  
Danbee Han ◽  
Yunji Kim ◽  
Hyunseung Byun ◽  
Wonjun Cho ◽  
Youngsoon Baek
Keyword(s):  
Reaction Temperature ◽  
Photoelectron Spectroscopy ◽  
Conversion Rate ◽  
Space Velocity ◽  
Molar Ratio ◽  
Co2 Conversion ◽  
X Ray Diffraction ◽  
Co2 Methanation ◽  
X Ray ◽  
Ch4 Production

Biogas contains more than 40% CO2 that can be removed to produce high quality CH4. Recently, CH4 production from CO2 methanation has been reported in several studies. In this study, CO2 methanation of biogas was performed over a 20 wt% Ni-Mg-Al catalyst, and the effects of CO2 conversion rate and CH4 selectivity were investigated as a function of CH4, O2, H2O, and N2 compositions of the biogas. At a gas hourly space velocity (GHSV) of 30,000 h−1, the CO2 conversion rate was ~79.3% with a CH4 selectivity of 95%. In addition, the effects of the reaction temperature (200–450 °C), GHSV (21,000–50,000 h−1), and H2/CO2 molar ratio (3–5) on the CO2 conversion rate and CH4 selectivity over the 20 wt% Ni-Mg-Al catalyst were evaluated. The characteristics of the catalyst were analyzed using Brunauer–Emmett–Teller surface area analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The catalyst was stable for approximately 200 h at a GHSV of 30,000 h−1 and a reaction temperature of 350 °C. CO2 conversion and CH4 selectivity were maintained at 75% and 93%, respectively, and the catalyst was therefore concluded to exhibit stable activity.

Polymorphism of felodipine co-crystals with 4,4′-bipyridine

CrystEngComm ◽  
2014 ◽  
Vol 16 (29) ◽  
pp. 6603-6611 ◽  
Author(s):  
Artem O. Surov ◽  
Katarzyna A. Solanko ◽  
Andrew D. Bond ◽  
Annette Bauer-Brandl ◽  
German L. Perlovich
Keyword(s):  
Blocking Agent ◽  
Solution Calorimetry ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Hirshfeld Surfaces ◽  
Channel Blocking ◽  
Polymorphic Forms ◽  
Hirshfeld Surfaces Analysis

The calcium-channel blocking agent felodipine forms co-crystals with 4,4′-bipyridine with 1 : 1 and 2 : 1 molar ratios. The co-crystal with 1 : 1 molar ratio exists in two polymorphic forms. The co-crystals polymorphism was investigated by X-ray diffraction, DSC, solution calorimetry and Hirshfeld surfaces analysis.

Synthesis of Single-Phased BaTi2O5 Powders by Arc-Melting

2011 ◽  
Vol 279 ◽  
pp. 44-48 ◽  
Author(s):  
Jian Peng ◽  
Chuan Bin Wang ◽  
Ling Li ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Raman Spectra ◽  
Main Phase ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Arc Melting

Arc-melting was employed to synthesize BaTi2O5 powders by fast melting the reagent mixture of BaCO3 and TiO2 with different molar ratios (0.90~1.05:2). The influence of molar ratios of BaCO3 to TiO2 on the phase of the powders derived from arc-melting was investigated by X-ray diffraction and Raman spectra. When the molar ratio was larger than 0.95:2, a little amount of Ba-rich compound Ba2TiO4 was produced besides the main phase of BaTi2O5. Ti-rich compound Ba6Ti17O40, BaTi2O9 and TiO2 began to appear at the ratios ranging from 0.90:2 to 0.95:2. Single-phased BaTi2O5 powders were obtained by arc-melting the reagent mixture with the molar ratio of 0.95:2.

Gold Clustering at Dimethylsulfoximine Me2S(O)NH

2000 ◽  
Vol 55 (10) ◽  
pp. 889-894 ◽  
Author(s):  
Armin Hamel ◽  
Christian Hollatz ◽  
Annette Schier ◽  
Hubert Schmidbaur
Keyword(s):  
Nitrogen Atom ◽  
Dinuclear Complex ◽  
Trinuclear Complex ◽  
Molar Ratio ◽  
High Yield ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Pyramidal Configuration ◽  
Unknown Structure

Abstract Gold Clustering, Dimethylsulfoximine Polyaurated complexes of the dimethylsulfoximide anion [Me2S(O)N]- have been prepared by reacting N-trimethylsilyl-dimethylsulfoximide with [(Ph3P)Au]BF4 in various molar ratios. With one or two equivalents of the gold(I) reagent only the dinuclear complex is obtained in high yield: {[(Ph3P)Au]2NS(O)Me2}+ BF4- . With three or four equivalents only the trinuclear complex is produced: {[(Ph3P)Au]3NS(O)Me2}2+ 2 BF4- . No mono- or tetra-auration was observed, respectively. The composition of the compounds has been confirmed by analytical and spectroscopic data, and the crystal structure of the dinuclear compound has been determined by single crystal X-ray diffraction of the dichloromethane solvate. The two gold atoms are found to be coordinated to the nitrogen atom with a small Au-N-Au angle of only 92.3(3)° and a short Au-Au distance of 2.9900(5) Å. The nitrogen atom is in a distorted trigonal pyramidal configuration which allows an intramolecular SO-Au contact. For the trinuclear complex a structure with a tetracoordinate nitrogen atom [SNAU3] is proposed which is analogous to the corresponding complexes of phosphinimines R3P=NH. With the ditertiary phosphine Ph2PCH2Ch2PPh2 (dppe) a cyclic dinuclear complex (dppe)Au2[NS(0 )Me2]BF4 can be synthesized starting from (dppe)Au2Cl2. The reaction of the phosphine-rich precursor [(Ph3P)2Au]BF4 with Me3SiNS(0 )Me2 in the molar ratio 2:1 affords a binuclear complex {[(Ph3P)2Au]2NS(0 )Me2}BF4 of an as yet unknown structure

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