scholarly journals Levulinic Acid Production from Delignified Rice Husk Waste over Manganese Catalysts: Heterogeneous Versus Homogeneous

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 327 ◽  
Author(s):  
Arnia Putri Pratama ◽  
Dyah Utami Cahyaning Rahayu ◽  
Yuni Krisyuningsih Krisnandi
Keyword(s):  
Reaction Time ◽  
Rice Husk ◽  
Levulinic Acid ◽  
Main Product ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Hydroxymethyl Furfural ◽  
Manganese Catalysts ◽  
Heterogenous Catalyst ◽  
Wet Impregnation Method

Delignified rice husk waste (25.66% (wt) cellulose) was converted to levulinic acid using three types of manganese catalysts, i.e., the Mn3O4/hierarchical ZSM-5 zeolite and Mn3O4 heterogenous catalysts, as well as Mn(II) ion homogeneous counterpart. The hierarchical ZSM-5 zeolite was prepared using the double template method and modified with Mn3O4 through wet-impregnation method. The structure and physicochemical properties of the catalyst materials were determined using several solid-state characterization techniques. The reaction was conducted in a 200 mL-three neck-round bottom flask at 100 °C and 130 °C for a certain reaction time in the presence of 10% (v/v) phosphoric acid and 2% (v/v) H2O2 aqueous solution, and the product was analyzed using HPLC. In general, 5-hydroxymethyl furfural (5-HMF) as the intermediate product was produced after 2 h and decreased after 4 h reaction time. To conclude, the Mn3O4/hierarchical ZSM-5 heterogenous catalyst gave the highest yield (wt %) of levulinic acid (39.75% and 27.60%, respectively) as the main product, after 8 h reaction time.

scholarly journals Ni Supported on Natural Clays as a Catalyst for the Transformation of Levulinic Acid into γ-Valerolactone without the Addition of Molecular Hydrogen

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3448
Author(s):  
Adrián García ◽  
Rut Sanchis ◽  
Francisco J. Llopis ◽  
Isabel Vázquez ◽  
María Pilar Pico ◽  
...  
Keyword(s):  
Levulinic Acid ◽  
Low Cost ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Surface Areas ◽  
Natural Clays ◽  
Wet Impregnation Method ◽  
Clay Materials ◽  
Automotive Fuels

γ-Valerolactone (GVL) is a valuable chemical that can be used as a clean additive for automotive fuels. This compound can be produced from biomass-derived compounds. Levulinic acid (LA) is a compound that can be obtained easily from biomass and it can be transformed into GVL by dehydration and hydrogenation using metallic catalysts. In this work, catalysts of Ni (a non-noble metal) supported on a series of natural and low-cost clay-materials have been tested in the transformation of LA into GVL. Catalysts were prepared by a modified wet impregnation method using oxalic acid trying to facilitate a suitable metal dispersion. The supports employed are attapulgite and two sepiolites with different surface areas. Reaction tests have been undertaken using an aqueous medium at moderate reaction temperatures of 120 and 180 °C. Three types of experiments were undertaken: (i) without H2 source, (ii) using formic acid (FA) as hydrogen source and (iii) using Zn in order to transform water in hydrogen through the reaction Zn + H2O → ZnO + H2. The best results have been obtained combining Zn (which plays a double role as a reactant for hydrogen formation and as a catalyst) and Ni/attapulgite. Yields to GVL higher than 98% have been obtained at 180 °C in the best cases. The best catalytic performance has been related to the presence of tiny Ni particles as nickel crystallites larger than 4 nm were not present in the most efficient catalysts.

scholarly journals Nickel-based perovskite catalysts: synthesis and catalytic tests in the production of syngas

Cerâmica ◽  
2018 ◽  
Vol 64 (371) ◽  
pp. 436-442 ◽  
Author(s):  
E. O. Moraes Júnior ◽  
J. O. Leite ◽  
A. G. Santos ◽  
M. J. B. Souza ◽  
A. M. Garrido Pedrosa
Keyword(s):  
Impregnation Method ◽  
X Ray Diffraction ◽  
Organic Precursor ◽  
Wet Impregnation ◽  
Partial Oxidation Reaction ◽  
Conversion Level ◽  
Temperature Programmed ◽  
Perovskite Type ◽  
Wet Impregnation Method ◽  
H2 Selectivity

Abstract La1-xSrxNiO3 (x= 0.0, 0.3 or 0.7) perovskite-type oxides were synthesized using the modified proteic gel method and using collagen as an organic precursor. Catalysts of La1-xSrxNiO3/Al2O3 were obtained using the wet impregnation method. The synthesized catalysts were characterized by X-ray diffraction, surface area and temperature-programmed reduction. The catalysts were evaluated in the partial oxidation reaction of methane, and the levels of selectivity to CO, CO2, H2 and H2O were determined. Among the catalysts studied, the catalyst LaNiO3/Al2O3 had the highest methane conversion level (78%) and higher H2 selectivity (55%).

scholarly journals Catalytic Activity Of Cu/η-Al2O3 Catalysts Prepared From Aluminum Scraps In The NH3-SCO and in the NH3-SCR of NO

2021 ◽  
Author(s):  
Nawel Jr ◽  
Thabet Makhlouf ◽  
Gerard Delahay ◽  
Hassib Tounsi
Keyword(s):  
Catalytic Oxidation ◽  
Catalytic Reduction ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Reduction Of No ◽  
Evaporation Method ◽  
Nh3 Scr ◽  
Scr Of No ◽  
Selective Catalytic Oxidation ◽  
Wet Impregnation Method

Abstract Copper loaded η-alumina catalysts with different copper contents have been prepared by impregnation/evaporation method. The catalysts were characterized by XRD, FTIR, BET, UV–vis, H2-TPR and evaluated in the selective catalytic reduction of NO by NH3 and in the selective catalytic oxidation of NH3. The characterization techniques showed that the impregnation/evaporation method permits to obtain highly dispersed copper oxide species on the η-alumina surface when low amount of copper is used (1wt. % and 2 wt.%). The wet impregnation method made it possible to reach a well dispersion of the copper species on the surface of the alumina for the low copper contents Cu(1)-Al2O3 and Cu(2)-Al2O3. The latter justifies the similar behavior of Cu(1)-Al2O3) and Cu(2)-Al2O3 in the selective catalytic oxidation of NH3 where these catalysts exhibit a conversion of NH3 to N2 of the order of 100% at T > 500°C.

Effect of CNTs Support Diameter on Pt Particles Size and Distribution

2007 ◽  
Vol 119 ◽  
pp. 231-234
Author(s):  
Yong Hwan Kim ◽  
Yon Ki Seo ◽  
Young Rae Cho ◽  
Kwang Ho Kim ◽  
Won Sub Chung
Keyword(s):  
Electrochemical Impedance ◽  
Pt Catalyst ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Optimum Diameter ◽  
Electro Oxidation ◽  
Average Size ◽  
Wet Impregnation Method ◽  
Xrd And Tem ◽  
Supported Pt Catalyst

The Platinum catalysts on the carbon nanotubes(CNTs) supports of various diameters were prepared by wet impregnation method using H2PtCl6 precursor. The samples using 100nm, 15~20nm, 10~15nm and 5~10nm diameters of CNTs and carbon nanofibers(CNFs) are named Pt/t- CNFs, Pt/MWNTs20, Pt/MWNTs10 and Pt/MWNTs5, respectively. The effects of CNTs diameter on the Pt particle size and distribution were investigated by the means of powder XRD and TEM observation. In addition, the electro-catalytic characteristics for methanol electro-oxidation were estimated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. The average size of Pt particles increases as follows; Pt/MWNTs10 < Pt/MWNTs5 < Pt/MWNTs20 < Pt/t-CNFs. The electro-catalytic characteristics of Pt/MWNTs10 and Pt/MWNTs20 are found to be superior in comparison with the others. For preparation of the most effective supported Pt catalyst, the optimum diameter of CNTs support in the range of 10-20nm, is needed.

Preparation of Cr Metal Supported on Sulfated Zirconia Catalyst

2019 ◽  
Vol 948 ◽  
pp. 221-227
Author(s):  
Latifah Hauli ◽  
Karna Wijaya ◽  
Ria Armunanto
Keyword(s):  
Sulfated Zirconia ◽  
Reduction Process ◽  
Catalyst Preparation ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Zirconia Catalyst ◽  
Isotherm Adsorption ◽  
Sulfated Zirconia Catalyst ◽  
Adsorption Desorption ◽  
Wet Impregnation Method

Catalyst of Chromium (Cr) metal supported on sulfated zirconia (SZ) was prepared by wet impregnation method. This study aim to determine the optimal concentration of Cr metal that impregnated on SZ catalyst. Preparation of catalyst was conducted at different concentrations of Cr metal (0.5%, 1%, 1.5% (w/w)), impregnated on SZ catalyst, then followed by the calcinationand reduction process. Catalysts were charaterized by FTIR, XRD, XRF, SAA, TEM, and acidity test. The results showed the Cr/SZ 1% had the highest acidity value of 8.22 mmol/g which confirmed from FTIR spectra. All the crystal phase of these catalysts were in monoclinic. The specific surface area increased with the increasing of Cr metal concentration on SZ catalyst and the isotherm adsorption-desorption of N2 gas observed all the catalysts as mesoporous material. The impregnation process formed particles agglomeration.

scholarly journals {CeO2/Bi2Mo1−xRuxO6} and {Au/Bi2Mo1−xRuxO6} Catalysts for Low-Temperature CO Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 947 ◽  
Author(s):  
Edson Edain González ◽  
Ricardo Rangel ◽  
Javier Lara ◽  
Pascual Bartolo-Pérez ◽  
Juan José Alvarado-Gil ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Photoelectron Spectroscopy ◽  
Supported Catalysts ◽  
Pollutant Emissions ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
X Ray ◽  
Low Temperature Co Oxidation ◽  
Carbon Dioxide Co2 ◽  
Wet Impregnation Method

Nowadays, one of the most important challenges that humanity faces is to find alternative ways of reducing pollutant emissions. CeO2/Bi2Mo1−xRuxO6 and Au/Bi2Mo1−xRuxO6 catalysts were prepared to efficiently transform carbon monoxide (CO) to carbon dioxide (CO2) at low temperatures. The systems were prepared in a two-step process. First, Bi2Mo1−xRuxO6 supports were synthesized through the hydrothermal procedure under microwave heating. Then, CeO2 was deposited on Bi2Mo1−xRuxO6 using the wet impregnation method, while the incipient impregnation method was selected to deposit gold nanoparticles. The CeO2/Bi2Mo1−xRuxO6 and Au/Bi2Mo1−xRuxO6 catalysts were characterized using SEM microscopy and XRD. Furthermore, energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were used. Tests were carried out for the supported catalysts in CO oxidation, and high conversion values, nearing 100%, was observed in a temperature range of 100 to 250 °C. The results showed that the best system was the Au/Bi2Mo0.95Ru0.05O6 catalyst, with CO oxidation starting at 50 °C and reaching 100% conversion at 186 °C.

scholarly journals Deep oxidative desulfurization of model fuels catalysed by immobilized ionic liquid on MIL-100(Fe)

RSC Advances ◽  
2019 ◽  
Vol 9 (38) ◽  
pp. 21804-21809 ◽  
Author(s):  
WanXin Yang ◽  
Guoqing Guo ◽  
Zhihong Mei ◽  
Yinghao Yu
Keyword(s):  
Ionic Liquid ◽  
High Efficiency ◽  
Oxidative Desulfurization ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Wet Impregnation Method

ILs@MIL-100 composites were synthesized via the wet impregnation method and applied in deep oxidative desulfurization of gasoline with high efficiency.

CeO2 nanodots decorated ketjen black for high performance lithium–sulfur batteries

RSC Advances ◽  
2016 ◽  
Vol 6 (112) ◽  
pp. 111190-111196 ◽  
Author(s):  
Xinye Qian ◽  
Lina Jin ◽  
Lin Zhu ◽  
Shanshan Yao ◽  
Dewei Rao ◽  
...  
Keyword(s):  
High Performance ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Lithium Sulfur Battery ◽  
Lithium Sulfur Batteries ◽  
Sulfur Battery ◽  
Wet Impregnation Method ◽  
Lithium Sulfur

A CeO2 nanodots decorated ketjen black composite was fabricated by a simple wet impregnation method and used as the host of sulfur for a lithium–sulfur battery.

scholarly journals Oxidative dehydrogenation of isobutane over supported V-Mo mixed oxides

2010 ◽  
Vol 75 (8) ◽  
pp. 1115-1124 ◽  
Author(s):  
Gheorghiţa Mitran ◽  
Ioan-Cezar Marcu ◽  
Adriana Urdă ◽  
Ioan Săndulescu
Keyword(s):  
Oxidative Dehydrogenation ◽  
Mixed Oxides ◽  
Catalytic Performance ◽  
Molybdenum Oxides ◽  
Impregnation Method ◽  
N2 Adsorption ◽  
Wet Impregnation ◽  
Vis Spectroscopy ◽  
Wet Impregnation Method ◽  
Oxidative Dehydrogenation Of Isobutane

Vanadium-molybdenum oxides supported on Al2O3, CeO2 and TiO2 were prepared by a ?wet? impregnation method, characterized using DRX, N2 adsorption, UV-Vis spectroscopy, electrical conductivity measurements and tested in the oxidative dehydrogenation of isobutane. The catalytic performance in the oxidative dehydrogenation of isobutane at 400-550?C depended on the nature of support and on the content of VMoO species on the support. The catalysts supported on alumina were more active and selective than those supported on ceria and titania.

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