scholarly journals Oxidative Condensation of Furfural with Ethanol Using Pd-Based Catalysts: Influence of the Support

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1309
Author(s):  
Juan Antonio Cecilia ◽  
Carmen Pilar Jiménez-Gómez ◽  
Virginia Torres-Bujalance ◽  
Cristina García-Sancho ◽  
Ramón Moreno-Tost ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Value Added ◽  
Textural Properties ◽  
Catalytic Performance ◽  
Oxidative Condensation ◽  
X Ray ◽  
Basic Sites ◽  
Carbonaceous Deposits ◽  
Β Zeolite ◽  
Adsorption Desorption

PdO nanoparticles were deposited on several supports (β-zeolite, Al2O3, Fe2O3, MgO, and SiO2), which displayed different crystallinity, textural properties, and amount of acid and basic sites. These catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms at −196 °C, NH3 and CO2 thermoprogrammed desorption analyses (NH3- and CO2-TPD, and X-ray photoelectron spectroscopy (XPS). Pd-based catalysts were tested in the oxidative condensation of furfural with ethanol to obtain value-added chemicals. The catalytic results revealed high conversion values, although the presence of a high proportion of carbonaceous deposits, mainly in the case of the PdO supported on β-zeolite and Al2O3, is also noteworthy. The presence of basic sites led to a beneficial effect on the catalytic behavior, since the formation of carbonaceous deposits was minimized. Thus, the 2Pd-MgO (2 wt.% Pd) catalyst reached the highest yield of furan-2-acrolein (70%) after 3 h of reaction at 170 °C. This better catalytic performance can be explained by the high basicity of MgO, used as support, together with the large amount of available PdO, as inferred from XPS.

scholarly journals Synthesis of DME by CO2 hydrogenation over La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts

2017 ◽  
Vol 23 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Yajing Zhang ◽  
Yu Zhang ◽  
Fu Ding ◽  
Kangjun Wang ◽  
Wang Xiaolei ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Direct Synthesis ◽  
Catalytic Performance ◽  
Co2 Hydrogenation ◽  
Precipitation Method ◽  
X Ray ◽  
Temperature Programmed ◽  
And Performance ◽  
Co Precipitation ◽  
Adsorption Desorption

A series of La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts were prepared by an oxalate co-precipitation method. The catalysts were fully characterized by X-ray diffraction (XRD), N2 adsorption-desorption, hydrogen temperature pro-grammed reduction (H2-TPR), ammonia temperature programmed desorption (NH3-TPD), and X-ray photoelectron spectroscopy (XPS) techniques. The effect of the La2O3 content on the structure and performance of the catalysts was thoroughly investigated. The catalysts were evaluated for the direct synthesis of dimethyl ether (DME) from CO2 hydrogenation. The results displayed that La2O3 addition enhanced catalytic performance, and the maximal CO2 conversion (34.3%) and DME selectivity (57.3%) were obtained over the catalyst with 1% La2O3, which due to the smaller size of Cu species and a larger ratio of Cu+/Cu.

scholarly journals Cobalt Element Effect of Ternary Mesoporous Cerium Lanthanum Solid Solution for the Catalytic Conversion of Methanol and CO2 into Dimethyl Carbonate

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 270
Author(s):  
Xu Li ◽  
Hua Shi ◽  
Yunhan Gu ◽  
Qingyan Cheng ◽  
Yanji Wang
Keyword(s):  
Solid Solution ◽  
Oxygen Vacancy ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Dimethyl Carbonate ◽  
Catalytic Performance ◽  
X Ray ◽  
Assembly Method ◽  
Transmission Electron ◽  
Adsorption Desorption

A citric acid ligand assisted self-assembly method is used for the synthesis of ternary mesoporous cerium lanthanum solid solution doped with metal elements (Co, Zr, Mg). Their textural property was characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption, X-ray photoelectron spectroscopy and TPD techniques, and so on. The results of catalytic testing for synthesis of dimethyl carbonate (DMC) from CH3OH and CO2 indicated that the DMC yield reached 316 mmol/g on Ce-La-Co solid solution when the reaction temperature was 413 K and the reaction pressure was 8.0 MPa. It was found that Co had synergistic effect with La and Ce, doping of Co on the mesoporous Ce-La solid solution was helpful to increase the surface area of the catalyst, promote CO2 adsorption and activation, and improve the redox performance of solid solution catalyst. The conversion of Co2+ to Co3+ resulted in the continuous redox cycle between Ce4+ and Ce3+, and the oxygen vacancy content of the catalyst was increased. Studies have shown that the catalytic performance of Ce-La-Co solid solution is positively correlated with oxygen vacancy content. On this basis, the reaction mechanism of DMC synthesis from CO2 and CH3OH on the catalyst was speculated.

Synthesis of TiO2 and ZrO2 nanomaterials for the degradation of nerve agent simulants

2021 ◽  
Vol 11 (1) ◽  
pp. 105-110
Author(s):  
Dung Le Van ◽  
Phuong Dang Tuyet ◽  
Trinh Nguyen Duy ◽  
Manh Nguyen Ba
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Chemical Warfare Agent ◽  
Catalytic Performance ◽  
Sem Images ◽  
X Ray ◽  
Nitrophenyl Phosphate ◽  
Tio2 Nanomaterials ◽  
Adsorption Desorption

TiO2 and ZrO2 nanomaterials were successfully synthesized by sol gel method. Samples were characterized by X-ray difraction (XRD), Fourier-transform infrared spectroscopy (FTIR), N2 adsorption–desorption, Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS),  SEM images and TEM images of TiO2 and ZrO2 samples showed the particle size of 10–20 nm. The results have revealed highly porous structure of ZrO2 and TiO2 nanomaterials with specific surface area of 116 m2g-1 and 125 m2g-1, respectively. The TiO2 and ZrO2 materials were used as the degradation of dimethyl 4-nitrophenyl phosphate (DMNP) chemical warfare agent emulator. The ZrO2 nanomaterial exhibited highly catalytic performance of DMNP degradation and the conversion reached to the value of 90.64 %, after 120 min of reaction.

scholarly journals Propylsulfonic Acid Functionalized SBA-15 Mesoporous Silica as Efficient Catalysts for the Acetalization of Glycerol

Catalysts ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 297 ◽  
Author(s):  
Ruiyun Li ◽  
Heyuan Song ◽  
Jing Chen
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Structural Parameters ◽  
Catalytic Performance ◽  
Cyclic Acetals ◽  
X Ray ◽  
Composition And Structure ◽  
Optimum Reaction ◽  
Adsorption Desorption ◽  
And Control

As the main by-product obtained from biomass, glycerol could be converted into valuable chemicals. Tunable propylsulfonic acid functionalized SBA-15 and KIT-6 with different structural parameters have been prepared by different methods while using 3-mercaptopropyltrimethoxysilane (MPTMS) as the source of sulfur. The composition and structure of the synthesized catalysts have been well-characterized by N2 adsorption-desorption (BET), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The catalytic performance of the prepared catalysts have been evaluated and compared in glycerol acetalization with formaldehyde to the mixture of 1,3-dioxane-5-ol and 1,3-dioxolane-4-methanol. Optimum reaction parameters were investigated to enhance the yield of products and control the distribution of glycerol formals. More than 90% yield of cyclic acetals were obtained with the ratio of two isomers 5R to 6R of 42:58.

Synthesis and catalytic performance of MCM-41 modified with tetracarboxylphthalocyanine

2013 ◽  
Vol 67 (4) ◽  
Author(s):  
Ya-Ping Zhang ◽  
Ke-Chuang Xue ◽  
Wei-Ping Zhang ◽  
Chao Song ◽  
Rong-Lan Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Performance ◽  
Conversion Ratio ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
N2 Adsorption ◽  
X Ray ◽  
Adsorption Desorption ◽  
Mcm 41 ◽  
Scanning Electron

AbstractA series of tetracarboxylphthalocyanines (MPc(COOH)4, M = H, Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II)) were anchored onto MCM-41 by the following procedures: functionalization of MCM-41 with (EtO)3SiCH2CH2CH2NH2 reacting with surface Si-OH, and anchoring MPc(COOH)4 onto MCM-41 with a substitution reaction between chloroformyl and amino groups. The samples were characterized by infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, N2 adsorption-desorption, and X-ray photoelectron spectroscopy. Catalytic activity of oxidation was tested using solutions of ethanethiol in petroleum ether and thiophene in octane; CoPc-CONH-MCM-41 displayed the highest conversion ratio of 90.15 % and 93.79 %, respectively.

scholarly journals Influence of Structure-modifying Agents in the Synthesis of Zr-doped SBA-15 Silica and Their Use as Catalysts in the Furfural Hydrogenation to Obtain High Value-added Products through the Meerwein-Ponndorf-Verley Reduction

2019 ◽  
Vol 20 (4) ◽  
pp. 828 ◽  
Author(s):  
Raquel López-Asensio ◽  
Carmen Jiménez Gómez ◽  
Cristina García Sancho ◽  
Ramón Moreno-Tost ◽  
Juan Cecilia ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Furfuryl Alcohol ◽  
Porous Silica ◽  
Value Added ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
Furfural Hydrogenation ◽  
Adsorption Desorption

Zr-doped mesoporous silicas with different textural parameters have been synthesized in the presence of structure-modifying agents, and then characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption at −196 °C, NH3 thermoprogrammed desorption (NH3–TPD), CO2 thermoprogrammed desorption (CO2–TPD), and X-ray photoelectron spectroscopy (XPS). These porous materials were evaluated in the furfural hydrogenation through the Meerwein-Ponndorf-Verley (MPV) reaction. The catalytic results indicate that the catalyst synthesized under hydrothermal conditions and adding a pore expander agent is more active and selective to furfuryl alcohol. However, the Zr-doped porous silica catalysts that were synthesized at room temperature, which possess narrow pore sizes, tend to form i-propyl furfuryl and difurfuryl ethers, coming from etherification between furfuryl alcohol (FOL) and isopropanol molecules (used as H-donor) by a SN2 mechanism.

scholarly journals The effect of neodymium and yttrium on benzofuran hydrodeoxygenation performance over a bulk Ni2P catalyst

2019 ◽  
Vol 44 (1) ◽  
pp. 29-36
Author(s):  
Hua Song ◽  
Xueya Dai ◽  
Nan Jiang ◽  
Zijin Yan ◽  
Tianhan Zhu ◽  
...  
Keyword(s):  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Free Products ◽  
X Ray ◽  
Highly Dispersed ◽  
Adsorption Desorption

Neodymium (Nd)- or yttrium (Y)- modified bulk Ni2P catalysts (Nd-Ni2P or Y-Ni2P) have been successfully prepared and their catalytic performance in benzofuran hydrodeoxygenation have been investigated. The as-prepared catalysts were characterised by X-ray diffraction, N2 adsorption–desorption, CO uptake and X-ray photoelectron spectroscopy. The addition of Nd or Y, especially Nd, can increase the surface area of the catalysts and promote the formation of smaller and more highly dispersed Ni2P particles. The Nd-Ni2P catalyst showed the highest benzofuran hydrodeoxygenation activity of 95.3% and the O-free products yield of 74.6%, which gives an increase of 25.3% and 35.4% when compared with that found for Ni2P.

scholarly journals Pristine and Magnetic Kenaf Fiber Biochar for Cd2+ Adsorption from Aqueous Solution

2021 ◽  
Vol 18 (15) ◽  
pp. 7949
Author(s):  
Anwar Ameen Hezam Saeed ◽  
Noorfidza Yub Harun ◽  
Suriati Sufian ◽  
Muhammad Roil Bilad ◽  
Zaki Yamani Zakaria ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Textural Properties ◽  
Ion Concentration ◽  
Solution Temperature ◽  
Maximum Adsorption Capacity ◽  
Magnetic Biochar ◽  
X Ray ◽  
Study Results ◽  
Capacity Surface

Development of strategies for removing heavy metals from aquatic environments is in high demand. Cadmium is one of the most dangerous metals in the environment, even under extremely low quantities. In this study, kenaf and magnetic biochar composite were prepared for the adsorption of Cd2+. The synthesized biochar was characterized using (a vibrating-sample magnetometer VSM), Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The adsorption batch study was carried out to investigate the influence of pH, kinetics, isotherm, and thermodynamics on Cd2+ adsorption. The characterization results demonstrated that the biochar contained iron particles that help in improving the textural properties (i.e., surface area and pore volume), increasing the number of oxygen-containing groups, and forming inner-sphere complexes with oxygen-containing groups. The adsorption study results show that optimum adsorption was achieved under pH 5–6. An increase in initial ion concentration and solution temperature resulted in increased adsorption capacity. Surface modification of biochar using iron oxide for imposing magnetic property allowed for easy separation by external magnet and regeneration. The magnetic biochar composite also showed a higher affinity to Cd2+ than the pristine biochar. The adsorption data fit well with the pseudo-second-order and the Langmuir isotherm, with the maximum adsorption capacity of 47.90 mg/g.

scholarly journals Pore Modification and Phosphorus Doping Effect on Phosphoric Acid-Activated Fe-N-C for Alkaline Oxygen Reduction Reaction

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1519
Author(s):  
Jong Gyeong Kim ◽  
Sunghoon Han ◽  
Chanho Pak
Keyword(s):  
Phosphoric Acid ◽  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Electronic States ◽  
Nitrogen Adsorption ◽  
Reduction Reaction ◽  
Phosphorus Doping ◽  
X Ray ◽  
Precious Metal Catalysts ◽  
Adsorption Desorption

The price and scarcity of platinum has driven up the demand for non-precious metal catalysts such as Fe-N-C. In this study, the effects of phosphoric acid (PA) activation and phosphorus doping were investigated using Fe-N-C catalysts prepared using SBA-15 as a sacrificial template. The physical and structural changes caused by the addition of PA were analyzed by nitrogen adsorption/desorption and X-ray diffraction. Analysis of the electronic states of Fe, N, and P were conducted by X-ray photoelectron spectroscopy. The amount and size of micropores varied depending on the PA content, with changes in pore structure observed using 0.066 g of PA. The electronic states of Fe and N did not change significantly after treatment with PA, and P was mainly found in states bonded to oxygen or carbon. When 0.135 g of PA was introduced per 1 g of silica, a catalytic activity which was increased slightly by 10 mV at −3 mA/cm2 was observed. A change in Fe-N-C stability was also observed through the introduction of PA.

FeYO3@rGO nanocomposites: Synthesis, characterization and application in photooxidative degradation of atrazine under visible light

2021 ◽  
Vol 11 (5) ◽  
pp. 706-716
Author(s):  
Nada D. Al-Khthami ◽  
Tariq Altalhi ◽  
Mohammed Alsawat ◽  
Mohamed S. Amin ◽  
Yousef G. Alghamdi ◽  
...  
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Structural Surface ◽  
Adsorption Desorption

Different organic pollutants have been remediated photo catalytically by applying perovskite photocatalysts. Atrazine (ATR) is a pesticide commonly detected as a pollutant in drinking, surface and ground water. Herein, FeYO3@rGO heterojunction was synthesized and applied for photooxidation decomposition of ATR. First, FeYO 3nanoparticles (NPs) were prepared via routine sol-gel. After that, FeYO3 NPs were successfully incorporated with different percentages (5, 10, 15 and 20 wt.%) of reduced graphene oxide (rGO) in the synthesis of novel FeYO3@rGO photocatalyst. Morphological, structural, surface, optoelectrical and optical characteristics of constructed materials were identified via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), adsorption/desorption isotherms, diffusive reflectance (DR) spectra, and photoluminescence response (PL). Furthermore, photocatalytic achievement of the constructed materials was evaluated via photooxidative degradation of ATR. Various investigations affirmed the usefulness of rGO incorporation on the advancement of formed photocatalysts. Actually, novel nanocomposite containing rGO (15 wt.%) possessed diminished bandgap energy, as well as magnified visible light absorption. Furthermore, such nanocomposite presented exceptional photocatalytic achievement when exposed to visible light as ATR was perfectly photooxidized over finite amount (1.6 g · L-1) from the optimized photocatalyst when illuminated for 30 min. The advanced photocatalytic performance of constructed heterojunctions could be accredited mainly to depressed recombination amid induced charges. The constructed FeYO3@rGO nanocomposite is labelled as efficient photocatalyst for remediation of herbicides from aquatic environments.

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