Hybrid CaO/ZnFe2O4 Modified with Al2O3 as a Green Catalyst for Biodiesel Production from Waste Cooking Oil

In this work, biodiesel was produced from waste cooking oil (WCO) via a green catalyst of CaO-ZnFe2O4 modified Al2O3. The catalyst was characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray (EDX), SEM-mapping, Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM) analyses. The catalyst performance was studied in the transesterification reaction of WCO conversion to biodiesel. The catalytic activity increased with the combination of nanoparticles effect and support catalysts obtained biodiesel yield of nano-Al2O3, nano-CaO, ZnFe2O4, CaO-ZnFe2O4, and CaO-ZnFe2O4/Al2O3 is 36.86%, 67.16%, 74.83%, 86.54%, and 93.41%, respectively. The best biodiesel yield was 93.41% with a mass ratio of Al2O3 to CaO-ZnFe2O4 (2:1). The physicochemical properties (acid number, density, kinematic viscosity, flash point, and cetane number) of biodiesel under the optimal conditions agreed with the ASTM standard. These results show that the developed nanocomposite has great potential to reduce biodiesel production costs because derived from WCO. In conclusion, CaO-ZnFe2O4 modified Al2O3 as a catalyst has a high potential for biodiesel production on a large scale

Cellulose and TiO2–ZrO2 Nanocomposite as a Catalyst for Glucose Conversion to 5-EMF

This work demonstrated the use of green material catalysts, produced from Sengon sawdust waste, to obtain nanocellulose biopolymers. The green material catalysts were utilized as catalysts support of TiO2−ZrO2 binary oxide in the form of nanocomposite materials with superior synergistic properties. The isolation of nanocellulose was achieved using a hydrolysis method with a yield of 63.40%. The TiO2 and ZrO2 nanoparticles have average particle sizes of around 25 and 15 nm, respectively, and the binary oxides of TiO2–ZrO2 pretained an average particle size of 30 nm were used. Furthermore, the nanocellulose combined with the TiO2−ZrO2 binary oxide had formed a cellulose/TiO2−ZrO2 nanocomposite with an average particle size of 30 nm. This indicates that the supporting nanocellulose can stabilize the nanoparticles and avoid aggregation. Moreover, the nanocomposites can be used as a catalyst for the conversion of glucose to 5-ethoxymethylfurfural (5-EMF). The catalytic activity increased with the nanoparticle effect obtained ZrO2, TiO2, TiO2-ZrO2, and cellulose and TiO2-ZrO2 nanocomposite, in 15.50%, 20.20%, 35.20%, and 45.50% yields, respectively. The best yield of 5-EMF was 45.50%, with reaction conditions of 1:1 TiO2–ZrO2 ratio, 4 h reaction time, and 160 °C reaction temperature. The use of nanocellulose biopolymer generated from Sengon sawdust waste in Indonesia provides a promising catalyst support material as an alternative green catalyst. In addition, the glucose carbohydrates can be converted to biofuel feedstocks in the development of a renewable alternative energy. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

PREPARATION OF ELECTROCHEMICALLY IMMOBILIZED IRON ON THIN FILM FAUJASITE-NANOZEOLITE MODIFIED GLASSY CARBON

PREPARATION OF ELECTROCHEMICALLY IMMOBILIZED IRON ON THIN FILM FAUJASITE-NANOZEOLITE MODIFIED GLASSY CARBON. Metal iron that electrochemically immobilized on thin film faujasite type of nanozeolite (FAU-nanozeolite) grown on polyelectrolyte (PDDA, PSS, PDDA layers) modified glassy carbon has been prepared. Thin film of FAU-type nanozeolite was synthesized using seeding method. The seeded modified-glassy carbon then was immersed in FAU colloidal suspension at 100 oC for certain period. XRD patterns of the seed and as-synthesized zeolite powder have similarity with the patterns from standard NaY zeolite. SEM images of thin film nanozeolite also show the appearance of crystals with homogeneous size of about 100 nm) of the nanozeolite thin film. However, it can also be seen that the crystals actually consist of smaller particles with size < 100 nm. The EDS mapping of the surface indicates that after electrochemical treatment, the surface of thin film consists of about 0.30% (w/w) iron that spread evently both on the surface covered by nanozeolite thin film and that from modified glassy carbon

Modification of Mixed Structure Tio2 Nanoporous-nanotube Arrays with Cds Nano Particle and Their Photo Electro Chemicalproperties

MODIFICATION OF MIXED STRUCTURE TiO2 NANOPOROUS-NANOTUBE ARRAYS WITH CdS NANO PARTICLE AND THEIR PHOTO ELECTRO CHEMICALPROPERTIES. In thiswork, a mixed structure TiO2 with a top nanoporous layer and an underneath highly ordered nanotube arrays layer (TNPs-NTAs) were prepared by anodic oxidation of Ti foil under controlled anodization time in an electrolyte containing fluoride ion,water and ethylene glycol. CdS nanoparticles (NPs) was deposited onto the mixed structure of TiO2 by Successive Ionic Layer Adsorption and Reaction (SILAR) with an aim toward tuning the photoelectrochemical performance to visible region. Themorphology, elemental composition, crystal structure, optical properties and photoelectrochemical performance of TNPs-NTs and CdS modified (CdS/TNP-NTAs) samples were characterized by Field Emisi Scanning Electron Microscope (FESEM), Electron Dispersive Spectroscopy (EDS), X-Ray Diffractometer (XRD), Diffuse Reflactance Spectroscopy (DRS) and electrochemical working station respectively. The results indicate that CdS nanoparticles uniformly decorated on top of surface and inner wall of TNPs-NTs sample. No clogging of CdS-NP at the mouth TNPs-NTAs was observed. The CdS/TNP-NTs show an increasing in the visible light adsorption and photocurrent response. Under white light illumination (9.93 mW/cm2), we found that the CdS/TNPs-NTAs have an optimum photocurrent density of 1.16 mA/cm2 , corresponding to energy photoconversion efficiency of 9.75%, which is 7 times higher than that of the bare TiO2 (TNPs-NTAs). The increase of photocurrent is attributed to the enhancement of charge separation efficiency and improved electron transport

MODIFICATION OF MIXED STRUCTURE TiO2 NANOPOROUS-NANOTUBE ARRAYS WITH CdS NANO PARTICLE AND THEIR PHOTO ELECTRO CHEMICALPROPERTIES

MODIFICATION OF MIXED STRUCTURE TiO2 NANOPOROUS-NANOTUBE ARRAYS WITH CdS NANO PARTICLE AND THEIR PHOTO ELECTRO CHEMICALPROPERTIES. In thiswork, a mixed structure TiO2 with a top nanoporous layer and an underneath highly ordered nanotube arrays layer (TNPs-NTAs) were prepared by anodic oxidation of Ti foil under controlled anodization time in an electrolyte containing fluoride ion,water and ethylene glycol. CdS nanoparticles (NPs) was deposited onto the mixed structure of TiO2 by Successive Ionic Layer Adsorption and Reaction (SILAR) with an aim toward tuning the photoelectrochemical performance to visible region. Themorphology, elemental composition, crystal structure, optical properties and photoelectrochemical performance of TNPs-NTs and CdS modified (CdS/TNP-NTAs) samples were characterized by Field Emisi Scanning Electron Microscope (FESEM), Electron Dispersive Spectroscopy (EDS), X-Ray Diffractometer (XRD), Diffuse Reflactance Spectroscopy (DRS) and electrochemical working station respectively. The results indicate that CdS nanoparticles uniformly decorated on top of surface and inner wall of TNPs-NTs sample. No clogging of CdS-NP at the mouth TNPs-NTAs was observed. The CdS/TNP-NTs show an increasing in the visible light adsorption and photocurrent response. Under white light illumination (9.93 mW/cm2), we found that the CdS/TNPs-NTAs have an optimum photocurrent density of 1.16 mA/cm2 , corresponding to energy photoconversion efficiency of 9.75%, which is 7 times higher than that of the bare TiO2 (TNPs-NTAs). The increase of photocurrent is attributed to the enhancement of charge separation efficiency and improved electron transport

Comparison of Xylene and Ethyl Acetate as Solvent in the Isolation of Levulinic Acid from Conversion Reaction of Cellulose Rice Husk using Hierarchical Mn3O4/ZSM-5 Catalyst

Levulinic acid is a platform chemical. This compound can be derived from conversion cellulose in lignocellulosic biomass such as rice husk. Cellulose conversion to levulinic acid can be enhanced with the help of a catalyst. Hierarchical Mn3O4/ZSM-5 was used as a catalyst in this study, which was made by wet impregnation of ZSM-5 with Mn (II). Before the conversion reaction, rice husk was pretreated with various chemical and mechanical methods to increase the amount of cellulose. The chemical method used NaOH, while mechanical methods used variations of ball milling and ultrasonication in phosphoric acid. The pretreated rice husk was then converted to levulinic acid at 130°C for 10 h in H3PO4 40% and H2O2 30% using hierarchical Mn3O4/ZSM-5 as a catalyst. The highest levulinic acid yield of 11.70% was obtained from the delignification of rice husk. The product was then extracted to obtain pure levulinic acid via solvent extraction using xylene and ethyl acetate as the organic solvents. The GC-MS examination showed that ethyl acetate is the best solvent and esterification agent in separating the levulinic acid

Optimised synthesis and further structural diversity of ytterbium benzene-1,4-dicarboxylate MOFs

The optimisation of the crystallisation of the hydrothermally-stable metal–organic framework Yb6-MOF (Yb6(BDC)7(OH)4(H2O)4) to provide a reproducible one-step synthesis is achieved by use of the sodium salt of benzene-1,4-dicarboxylate (Na2BDC) as ligand precursor and control of pH with aqueous NaOH at 190 °C over 3 days. Phase purity is confirmed using powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). During exploration of synthesis conditions from the same set of chemical reagents, three further ytterbium benzene-1,4-dicarboxylates have been isolated and structurally characterised using single-crystal X-ray diffraction, with phase purity assessed by PXRD and TGA. UOW-3 (Yb2(H2O)6(BDC)3) crystallises by lowering pH, and has a relatively dense three-dimensionally connected structure with no Yb–O–Yb linkages but dimers of Yb bridged by BDC linkers lying in the ab plane with a pseudo, pillared-layered structure, where BDC connects along c. UOW-4 (Yb4(BDC)6(H2O)6) forms under the same chemical conditions but upon lowering the temperature to 100 °C, and this material again contains no Yb–O–Yb linkages, but chains of BDC-bridged Yb centres cross-linked to give a dense three-dimensional structure. Upon increasing pH of the synthesis mixture, the material UOW-5 forms, Yb5O(OH)8(BDC)2(HBDC), consisting of dense inorganic layers of ytterbium oxyhydroxide, cross linked by BDC and HBDC pillars. The formulation is supported by infrared spectroscopy, which provides evidence for the HBDC monoanion, and also the presence of a short O–O distance indicative of hydrogen bonding between a carboxylate OH and an oxide anion of the inorganic layer. UOW-3 and UOW-4 both convert to Yb6-MOF upon heating in water above their synthesis temperature, whereas UOW-5 is hydrothermally stable at 240 °C. The structures of the new materials are discussed in terms of ligand binding modes, and connectivity of metal centres, with comparison to other reported Yb-BDC phases in order to relate structural chemistry to their synthesis conditions and the hydrothermal stability of the materials