Synthesis and Characterization of Zeolite A from Industrial Fly Ash as a Green, Cost-Effective Cd and Pb Adsorbent for Wastewater Applications.

According to the large amount of fly ash waste generated from the use of lignite coal as the primary fuel for electricity generation in the Mae Moh district of Lampang province, Thailand, efforts have been made in waste management to reduce and repurpose this industrial byproduct. In this study, lignite coal fly ash was used to synthesize zeolite A adsorbents for the treatment of wastewater contaminated with heavy metals. Characterization of the synthesized zeolite using XRD, XRF, BET, and SEM methods confirmed that it is zeolite A, with a calculated Si/Al molar ratio of approximately 1.

Value-added bioproducts by bioethanol dehydrogenation to acetaldehyde through Cu and Zn modified biochar catalysts.

In this study, the efficiency of a series of biochar-supported Cu catalysts, biochar-supported Zn catalysts, and biochar-supported Cu-Zn catalysts was determined through bioethanol dehydrogenation to the high-value chemical, acetaldehyde. Each metal, with weight percentages of 10, 20, and 30, and the combination of Cu-Zn, including 10 wt% of Cu and Zn, 15 wt% of Cu - 5 wt% of Zn, and 15 wt% of Cu and Zn, were fully loaded onto biochar using an incipient wetness impregnation technique. Subsequently, all biocatalysts were subjected to bioethanol dehydrogenation reactions in a temperature range of 200-400 °C.

Effect of Strontium Modification in Mg-Al Mixed Oxide Catalysts on Product Distribution toward Catalytic Reaction of Ethanol.

The aim of this research was to examine the effect of strontium content in the MgAlO catalyst for the catalytic ethanol reaction on the product distribution. The structure of the catalysts and the actual amount of strontium on the catalysts were verified using XRD and ICP techniques, respectively. The acid and basic strength characteristics of catalysts were examined using NH-TPD and CO-TPD techniques, respectively.

Differences in Deterioration Behaviors of Cu/ZnO/AlO Catalysts with Different Cu Contents toward Hydrogenation of CO and CO.

The deterioration behaviors of Cu/ZnO/AlO (CZA) catalysts upon different Cu contents were elucidated. The fresh and spent catalysts after being used in CO and CO hydrogenation at 250 °C under atmospheric pressure were properly characterized using various techniques including X-ray powder diffraction, X-ray photoelectron spectroscopy, and temperature-programmed reduction for the changes of metal sites, while the textural and chemical properties and carbon deposition on spent CZA catalysts were analyzed by N physisorption, energy-dispersive X-ray spectroscopy, and temperature-programmed oxidation. During the hydrogenation reaction for both CO and CO, the unstable Cu site on the spent CZA catalyst having a low Cu loading (sCZA-L) was oxidized to CuO and the aggregation of metal crystallite sites (Cu-ZnO and ZnO) was observed.

A review on sensitivity of operating parameters on biogas catalysts for selective oxidation of Hydrogen Sulfide to elemental sulfur.

Hydrogen sulfide (HS) is a critical problem for biogas applications, such as electricity and heat generation, or the production of different chemical compounds, due to corrosion and toxic effluent gases. The selective catalytic oxidation of HS to S is the most promising way to eliminate HS from biogas due to the lack of effluents, therefore can be considered a green technology. The most extensively used catalysts for HS selective oxidation can be classified in two groups: metal oxide-based catalysts, including vanadium and iron oxides, and carbon-based catalysts.

Optimal Conditions for Butanol Production from Ethanol over MgAlO Catalyst Derived from Mg-Al Layer Double Hydroxides.

The MgAlO catalyst was obtained from thermal decomposition of the MgAl-LDH catalyst having Mg/Al molar ratio of 5. The catalytic Guerbet reaction of ethanol was investigated to determine the effect of WHSV and nitrogen flow rate on butanol production and product distribution. It was performed in a fixed-bed microreactor under continuous flow of vaporized ethanol mixed with N.

Comparative study on the effect of different copper loading on catalytic behaviors and activity of Cu/ZnO/AlO catalysts toward CO and CO hydrogenation.

The ternary Cu/ZnO/AlO (CZA) catalysts having different Cu loading were prepared by the co-precipitation method. Then, they were used in CO and CO hydrogenation to produce methanol under atmospheric pressure at 250 °C. The high Cu loading CZA catalyst (CZA-H) resulted in the enhancement of structural features and textural properties (e.

Development of a New Ternary AlO-HAP-Pd Catalyst for Diethyl Ether and Ethylene Production Using the Preferential Dehydration of Ethanol.

This study aims to convert ethanol to higher value-added products, particularly diethyl ether and ethylene using the catalytic dehydration of ethanol. Hence, the gas-phase dehydration of ethanol over AlO-HAP catalysts as such and modified by addition of palladium (Pd) in a microreactor was evaluated. The commercial AlO-HAP catalyst was first prepared by the physical mixing method, and then, the optimal ratio of the AlO-HAP catalyst (2:8 by wt %) was impregnated with Pd to develop a new functional catalyst to alter surface acidity.

Study of deactivation in mesocellular foam carbon (MCF-C) catalyst used in gas-phase dehydrogenation of ethanol.

Mesocellular foam carbon (MCF-C) is one the captivating materials for using in gas phase dehydrogenation of ethanol. Extraordinary, enlarge pore size, high surface area, high acidity, and spherical shape with interconnected pore for high diffusion. In contrary, the occurrence of the coke is a majority causes for inhibiting the active sites on catalyst surface.

Interconnected Micro, Meso, and Macro Porous Activated Carbon from Bacterial Nanocellulose for Superior Adsorption Properties and Effective Catalytic Performance.

The porous carbon (bacterial cellulose (BC)-activated carbon (AC)(BA)) prepared via two-step activation of bacterial nanocellulose by treatments with potassium hydroxide (KOH) and then phosphoric acid (HPO) solutions showed superior adsorption properties and effective performance as catalyst support. BC-AC(BA) had an open and interconnected multi-porous structure, consisting of micropores (0.23 cm/g), mesopores (0.

Role of Al in Na-ZSM-5 zeolite structure on catalyst stability in butene cracking reaction.

The Na-ZSM-5 catalysts (SiO/AlO molar ratio = 20, 35, and 50) were prepared by rapid crystallization method to investigate their performance in butene cracking reaction. The XRD, XRF, NH-TPD, FT-IR, TPO, UV-Vis, and H, Al, Si MAS NMR techniques were used to identify the physical and chemical properties of Na-ZSM-5 catalysts. The silanol group (Si-OH) was the main acid site of Na-ZSM-5, and it was proposed to be the active site for the butene cracking reaction.

Pd Modification and Supporting Effects on Catalytic Dehydration of Ethanol to Ethylene and Diethyl Ether over W/TiO Catalysts.

In the present work, the palladium (Pd) modification and supporting effect of W/TiO catalysts on catalytic ethanol dehydration to ethylene and diethyl ether were investigated. The Pd modification with different sequence of Pd and W impregnation on the catalysts was prepared by the incipient wetness impregnation technique. The catalyst characterization and activity testing revealed that the different sequence during impregnation influenced the physicochemical properties and ethanol conversion of catalyst.

A computational-experimental investigation on high ethylene selectivity in ethanol dehydration reaction found on WO/ZrO-activated carbon bi-support systems.

The high ethylene selectivity exhibited on the zirconia-activated-carbon bi-support catalyst is investigated by experiment and density functional theory-based (DFT) analysis. This bi-support catalyst systems prepared by the physical mixing method for the tungsten catalyst show a significant increase in ethylene selectivity up to 90% compared to the zirconia single support system (~58%) during the ethanol dehydration reaction. Besides, the optimal percent weight ratio of zirconia to activated carbon, which results in the highest ethanol conversion is 50:50.

Synthesis of mesoporous MFI zeolite via bacterial cellulose-derived carbon templating for fast adsorption of formaldehyde.

Mesoporous ZSM-5 (MFI) zeolite was synthesized by using bacterial cellulose-derived activated carbon (BC-AC500) with a high surface area as a hard template. Different ratios of BC-AC500 and zeolite precursor gel were prepared in a Teflon-lined autoclave and crystallized at 180 °C for 48 h in a rotating oven. The physicochemical properties of the samples were characterized by x-ray diffraction (XRD), scanning/transmission electron microscopies (SEM/TEM), and N physisorption techniques.

Fuel oil generated from the cogon grass-derived Al-Si ( (L.) Beauv) catalysed pyrolysis of waste plastics.

This research investigated pyrolysis as a potential method to manage plastic waste in Sichang Island, Thailand. Pyrolysis was chosen to convert waste plastic into fuel oil using Al-Si catalysts derived from cogon grass. The study consisted of three stages.

Oxidative Dehydrogenation of Ethanol over Vanadium- and Molybdenum-modified Mg-Al Mixed Oxide Derived from Hydrotalcite.

Hydrotalcite or Mg-Al LDHs were synthesized by co-precipitation method. The Mg-Al mixed oxide was then derived by calcination of hydrotalcite at 450°C. The metal modified catalysts (Mo/Mg-Al and V/Mg-Al) were prepared by incipient wetness impregnation method.

Effect of Calcination Temperature on Mg-Al Layered Double Hydroxides (LDH) as Promising Catalysts in Oxidative Dehydrogenation of Ethanol to Acetaldehyde.

Oxidative dehydrogenation of ethanol to acetaldehyde over Mg-Al layered double hydroxides (LDH) and their differently calcined derivative catalysts was investigated in this study. The Mg-Al catalysts were synthesized via co-precipitation method and calcined at different temperatures at 450°C, 600°C and 900°C. It revealed that the calcination temperature affected the physicochemical properties and the catalytic activity of these catalysts toward the oxidative dehydrogenation of ethanol.

Characterization of Different Si- and Al-based Catalysts with Pd Modification and Their Use for Catalytic Dehydration of Ethanol.

This study aims to investigate the production of ethylene and diethyl ether from ethanol via catalytic dehydration using Si- and Al-based catalysts with Pd modification. First, six catalysts including H-beta zeolite (HBZ), mixed phases of γ-χ-AlO (M-Al) and γ-AlO (G-Al) with and without Pd modification (0.5 wt%) were prepared.

Production of Ethylene through Ethanol Dehydration on SBA-15 Catalysts Synthesized by Sol-gel and One-step Hydrothermal Methods.

The present work deals with the catalytic performance of SBA-15 supported catalysts in the gas phase catalytic dehydration of ethanol in the temperature range of 200 to 400°C. The SBA-15 support was incorporated on a zirconium (Zr) and bimetal of zirconium and lanthanum (Zr-La) prepared by sol-gel (SG) and hydrothermal (HT) methods. The catalysts were characterized by means of N physisorption, SEM/EDX, and NH-TPD.

Effect of HCl Loading and Ethanol Concentration over HCl-Activated Clay Catalysts for Ethanol Dehydration to Ethylene.

Montmorillonite clay (MMT) is one of materials that can be "green material" due to its environmental safety. In this work, acid-activated MMT catalysts were prepared for the dehydration reaction of ethanol. To be the green process, the reaction with bioethanol was also studied.

Catalytic Ethanol Dehydration to Ethylene over Nanocrystalline χ- and γ-AlO Catalysts.

The study is aimed to investigate the combination of nanocrystalline γ- and χ- alumina that displays the attractive chemical and physical properties for the catalytic dehydration of ethanol. The correlation between the acid density and ethanol conversion was observed. The high acid density apparently results in high catalytic activity, especially for the equally mixed γ- and χ- phase alumina (G50C50).

Diethyl Ether Production during Catalytic Dehydration of Ethanol over Ru- and Pt- modified H-beta Zeolite Catalysts.

In the present study, the catalytic dehydration of ethanol over H-beta zeolite (HBZ) catalyst with ruthenium (Ru-HBZ) and platinum (Pt-HBZ) modification was investigated. Upon the reaction temperature between 200 and 400°C, it revealed that ethanol conversion and ethylene selectivity increased with increasing temperature for both Ru and Pt modification. At lower temperature (200 to 250°C), diethyl ether (DEE) was the major product.

Catalytic Ethanol Dehydration over Different Acid-activated Montmorillonite Clays.

In the present study, the catalytic dehydration of ethanol to obtain ethylene over montmorillonite clays (MMT) with mineral acid activation including H2SO4 (SA-MMT), HCl (HA-MMT) and HNO3 (NA-MMT) was investigated at temperature range of 200 to 400°C. It revealed that HA-MMT exhibited the highest catalytic activity. Ethanol conversion and ethylene selectivity were found to increase with increased reaction temperature.

Desorption of water from distinct step types on a curved silver crystal.

We have investigated the adsorption of H2O onto the A and B type steps on an Ag single crystal by temperature programmed desorption. For this study, we have used a curved crystal exposing a continuous range of surface structures ranging from [5(111) × (100)] via (111) to [5(111) × (110)]. LEED and STM studies verify that the curvature of our sample results predominantly from monoatomic steps.

Effect of EtOH/MgCl(2) molar ratios on the catalytic properties of MgCl(2)-SiO(2)/TiCl(4) Ziegler-Natta catalyst for ethylene polymerization.

MgCl(2)-SiO(2)/TiCl(4) Ziegler-Natta catalysts for ethylene polymerization were prepared by impregnation of MgCl(2) on SiO(2) in heptane and further treatment with TiCl(4). MgCl(2)·nEtOH adduct solutions were prepared with various EtOH/MgCl(2) molar ratios for preparation of the MgCl(2)-supported and MgCl(2)-SiO(2)-supported catalysts in order to investigate the effect on polymerization performance of both catalyst systems. The catalytic activities for ethylene polymerization decreased markedly with increased molar ratios of [EtOH]/[MgCl(2)] for the MgCl(2)-supported catalysts, while for the bi-supported catalysts, the activities only decreased slightly.