Synthesis and X-ray Analysis of Mn–Mo Mixed Metal Oxide Cluster with Cubic Framework

2000 ◽  
Vol 29 (11) ◽  
pp. 1342-1343 ◽  
Author(s):  
Koji Nishikawa ◽  
Isamu Kinoshita ◽  
Takanori Nishioka ◽  
Kiyoshi Isobe
Author(s):  
Mansoor Anbia ◽  
Sotoudeh Sedaghat ◽  
Samira Saleh ◽  
Sholeh Masoomi

The synthesized nanomaterials by two different methods were used as a catalyst in the transesterification of waste cooking oil to produce biodiesel. For both environmental and economic reasons, it is beneficial to produce biodiesel from waste cooking oils. It is desirable to help solve waste oil disposal by utilizing its oils as an inexpensive starting material in biodiesel synthesis. The structure, morphology, and surface properties of resulting nanocatalysts were characterized by X-ray Fluorescence Spectroscopy (XRF), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Energy Dispersive X-ray Spectroscopy (EDX) and N2 adsorption-desorption isotherms. The synthesized nanocatalysts' efficiency in the production of biodiesel was studied by Gas Chromatography (GC) as well as leaching amounts of surface active components of each catalyst investigated by the EDX technique. The reactions were performed at 65°C using a 9:1 methanol to oil ratio for 3 h. The results indicate that the impregnated mixed metal oxide catalyst ( Ca-MgAl) shows a higher surface area and better mechanical strength than the totally co-precipitated mixed metal oxide catalyst (CaMgAl(O)). Although both of the fully co-precipitated and impregnated catalysts represented about 90% of fatty acid methyl esters (FAME) yield the leaching of active calcium component was significantly reduced from 45.8% in precipitated CaMgAl(O) to 8% for the impregnated Ca-MgAl catalyst. This improved structure represents the advantage of the impregnation technique to co-precipitation procedure for fabrication of robust nanostructures.


Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 760
Author(s):  
Mujeeb Khan ◽  
Syed Farooq Adil ◽  
Mohamed E. Assal ◽  
Abdulrahman I. Alharthi ◽  
Mohammed Rafi Shaik ◽  
...  

Catalytic efficacy of metal-based catalysts can be significantly enhanced by doping graphene or its derivatives in the catalytic protocol. In continuation of previous work regarding the catalytic properties of highly-reduced graphene oxide (HRG), graphene-oxide (GO) doped mixed metal oxide-based nanocomposites, herein we report a simple, straightforward and solventless mechanochemical preparation of N-doped graphene (NDG)/mixed metal oxide-based nanocomposites of ZnO–MnCO3 (i.e., ZnO–MnCO3/(X%-NDG)), wherein N-doped graphene (NDG) is employed as a dopant. The nanocomposites were prepared by physical milling of separately fabricated NDG and ZnO–MnCO3 calcined at 300 °C through eco-friendly ball mill procedure. The as-obtained samples were characterized via X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), Raman, Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDX) and surface area analysis techniques. To explore the effectiveness of the obtained materials, liquid-phase dehydrogenation of benzyl alcohol (BOH) to benzaldehyde (BH) was chosen as a benchmark reaction using eco-friendly oxidant (O2) without adding any harmful surfactants or additives. During the systematic investigation of reaction, it was revealed that the ZnO–MnCO3/NDG catalyst exhibited very distinct specific-activity (80 mmol/h.g) with a 100% BOH conversion and <99% selectivity towards BH in a very short time. The mechanochemically synthesized NDG-based nanocomposite showed remarkable enhancement in the catalytic performance and increased surface area compared with the catalyst without graphene (i.e., ZnO–MnCO3). Under the optimum catalytic conditions, the catalyst successfully transformed various aromatic, heterocyclic, allylic, primary, secondary and aliphatic alcohols to their respective ketones and aldehydes with high selectively and convertibility without over-oxidation to acids. In addition, the ZnO–MnCO3/NDG was also recycled up to six times with no apparent loss in its efficacy.


Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 245
Author(s):  
Nugroho Pranyoto ◽  
Yuni Dewi Susanti ◽  
Immanuel Joseph Ondang ◽  
Artik Elisa Angkawijaya ◽  
Felycia Edi Soetaredjo ◽  
...  

The fast depletion of fossil fuels has attracted researchers worldwide to explore alternative biofuels, such as biodiesel. In general, the production of biodiesel is carried out via transesterification processes of vegetable oil with the presence of a suitable catalyst. A mixed metal oxide has shown to be a very attractive heterogeneous catalyst with a high performance. Most of the mixed metal oxide is made by using the general wetness impregnation method. A simple route to synthesize silane-modified mixed metal oxide (CaO-CuO/C6) catalysts has been successfully developed. A fluorocarbon surfactant and triblock copolymers (EO)106(PO)70(EO)106 were used to prevent the crystal agglomeration of carbonate salts (CaCO3-CuCO3) as the precursor to form CaO-CuO with a definite size and morphology. The materials show high potency as a catalyst in the transesterification process to produce biodiesel. The calcined co-precipitation product has a high crystallinity form, as confirmed by the XRD analysis. The synthesized catalyst was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). The mechanism of surface modification and the effects of the catalytic activity were also discussed. The biodiesel purity of the final product was analyzed by gas chromatography. The optimum biodiesel yield was 90.17% using the modified mixed metal oxide CaO-CuO/C6.


Sign in / Sign up

Export Citation Format

Share Document