Total Basic Sites Research Articles

Catalytic upgrading of Naomaohu coal pyrolysis volatiles over NiAl and NiLiAl oxides

Catalytic upgrading of volatiles is an essential technology to improve the product distribution of pyrolysis for the clean and efficient utilization of low-rank coals. In this work, novel acid-base bifunctional catalysts composed of Ni/Li/Al oxides were designed and prepared using LDH precursors with tunable chemical composition and structural properties. The catalysts were systematically characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), physisorption, NH3-temperature programmed desorption (NH3-TPD), CO2-temperature programmed desorption (CO2-TPD), H2-temperature programmed reduction (H2-TPR), and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). A two-stage fixed bed reactor was employed to evaluate the performance of the catalysts. Characterization results suggest that the crystal size of NiO and the surface area of the catalyst decreased with increasing Li content and decreasing Ni content in the catalyst, while the pore volume and pore diameter were positively correlated with Li content. Moreover, the addition of Li reduced the amount of weak acid sites and raised the amount of total basic sites. Consequently, the bifunctional catalysts boosted the yield of light tar and the contents of aromatics and phenols in tar. Specifically, with the highest total acid sites (569 μmol/g) promoting the cracking of heavy pitch components, Ni2.5Li0.5Al1 decreased the content of pitch in tar to 23.8 wt%, representing a 42.7 % drop from the corresponding non-catalytic pyrolysis. Accordingly, it improved the light tar yield to 7.2 wt%, which was 18 % higher than non-catalytic pyrolysis. 450 °C is identified as a suitable temperature for the catalytic upgrading of volatiles from Naomaohu coal; higher catalysis temperatures at 500 °C and 550 °C led to lower tar yield and lower phenols content, along with higher gas yield and more carbon deposition.

Effect of thermal treatment on zeolite for real-time gas sensing of oxygenated volatile organic compounds

The breathable air is severally polluted due to the emission of various pollutants like volatile organic compounds (VOCs) and dust particles of submicron sizes. These pollutants have several adverse health hazards, which can cause fatal accidents and mortalities. In the current study, we have modified the FAU type of Zeolite (ZE) with the Si/Al to 1 and treated at different temperatures (300–600 °C) in a 10% H2 + 90% N2 mixture to achieve different distributions of oxygen vacancies. The presence of oxygen vacancy and electrons in the lattice is confirmed by EDAX, XPS and ESR techniques. The charge irregularities generated due to trapped electrons are exploited for detection of different VOCs like acetone, ethyl methyl ketone, isopropyl alcohol, ethanol, n-hexane, and benzene using the scanning kelvin probe (SKP) technique. The oxygen vacancies raise the distribution of Lewis and Brønsted basic sites, which impacts the interaction of VOCs with the sample surface and the amount of VOCs uptake. The untreated ZE and treated at 600 °C (ZE600) exhibited n-type behavior with 13.8% oxygen deficient sites with ∼1.9 μmol/g of total basic sites and 3 μmol/g of total acidic sites. The thermal treatment for ZE600 leads to ∼280 folds enhancement in surface photovoltage towards acetone with ∼ 67% of recovery concerning untreated ZE.

Modification of Fresh-Water Clamshells (Pilsbryoconcha exilis compressa) as New Raw Material and its Application in the Biodiesel Production of Lard Oil

In the present work, the catalytic activity and stability of the Fresh-water Clamshells-derived CaO catalyst were investigated by the transesterification reaction of lard oil. The physicochemical properties of lard oil as a raw material for biodiesel production compared with palm oil were also studied. The obtained CaO_FWC was characterized by various analytical techniques to evaluate the physicochemical properties consisting of TGA, SEM, XRD, XRF, BET surface area, FT-IR, Hammett indicator method, and CO2-TPD. The results found that the fresh CaO_FWC showed the specific surface area, percentage of Ca element, total basic site, and basic strength of 8.293 m2g−1, 98.6 wt.%, 8.450 mmol g−1, and 15 < H_< 18.4, respectively which similar to CaO commercial grade. In addition, the fresh CaO_FWC catalyst also presented high catalytic activity that gave %FAME of lard oil more than 96.5 %. However, the CaO_FWC catalyst could only reuse 3 times with the catalytic activity slightly decreased, and %FAME remained higher than 95 %. While the stability of the CaO_FWC catalyst was tested by storage for a long time to 180 days, this experimental data suggested that the CaO_FWC catalyst could preserve for only 30 days, with the catalytic efficiency remaining similar to the fresh CaO_FWC. Furthermore, the preservation and reusability of the catalyst were also studied in terms of the kinetic rate of reaction for use as a database to optimize the reaction conditions. Finally, the fuel properties of biodiesel products derived from lard oil and palm oil as raw materials and catalyzed by CaO_FWC catalyst met the specified standards both of EN-14214 and ASTM-D6751. Therefore, all the results of this work were excellent databases for utilizing and adding value to the Fresh-water Clamshells and lard oil as biomass sources for further development and development as renewable and alternative energy in Thailand. HIGHLIGHTS The CaO catalyst obtained after calcination of the Fresh-water Clamshells has displayed excellent catalytic activity for the transesterification of lard oil with biodiesel conversion and FAME yield obtained under optimal conditions up to 96.86 % The Fresh-water Clamshells could stand promising resource for low-cost catalysts to lead the way for low-cost biodiesel The kinetic data can be used to optimize the biodiesel production process GRAPHICAL ABSTRACT

TiO2 Catalyzed Dihydroxyacetone (DHA) Conversion in Water: Evidence That This Model Reaction Probes Basicity in Addition to Acidity

In this paper, evidence is provided that the model reaction of aqueous dihydroxyacetone (DHA) conversion is as sensitive to the TiO2 catalysts' basicity as to their acidity. Two parallel pathways transformed DHA: while the pathway catalyzed by Lewis acid sites gave pyruvaldehyde (PA) and lactic acid (LA), the base-catalyzed route afforded fructose. This is demonstrated on a series of six commercial TiO2 samples and further confirmed by using two reference catalysts: niobic acid (NbOH), an acid catalyst, and a hydrotalcite (MgAlO), a basic catalyst. The original acid-base properties of the six commercial TiO2 with variable structure and texture were investigated first by conventional methods in gas phase (FTIR or microcalorimetry of pyridine, NH3 and CO2 adsorption). A linear relationship between the initial rates of DHA condensation into hexoses and the total basic sites densities is highlighted accounting for the water tolerance of the TiO2 basic sites whatever their strength. Rutile TiO2 samples were the most basic ones. Besides, only the strongest TiO2 Lewis acid sites were shown to be water tolerant and efficient for PA and LA formation.

Self-combustion Ni and Co-based perovskites as catalyst precursors for ammonia decomposition. Effect of Ce and Mg doping

LaCo1-xNixO3 perovskites have been synthesized by self-combustion, characterized, and examined as catalyst precursors for the COx-free hydrogen production from catalytic ammonia decomposition at low temperatures. The influence of the cobalt content as well as the addition of two dopant in different amount was studied and optimized. Small Ni crystallite size and high total basic sites were found to remarkably enhance the catalytic activity. Moreover, bimetallic perovskites generated cobalt/nickel in higher size, higher impurities and lower active sites than pure nickel perovskite, which decreased the ammonia conversion. On the other hand, the addition of dopant in adequate amount over pure Ni perovskite (La0.1A0.9NiO3; A = Ce or Mg) generated catalyst with low nickel crystallite size and high basicity delivering superior catalytic performance. Catalysts were demonstrated to be stable for at least 40 h. In fact, 96 % and 98 % ammonia conversion were achieved at low temperature (400 °C), when La0.1Ce0.9NiO3 and La0.1Mg0.9NiO3 were employed, resulting from the synergic effect between La-Ce and Ni-Mg-La. Presenting the Mg-doped perovskite the highest catalytic activity at the mild temperature of 350 °C.This study provides new insight in designing diverse catalyst precursors to develop economic and efficient catalysts to achieve high ammonia conversion (high hydrogen production) at low temperature and enhance the ammonia perspective as hydrogen carrier toward the ‘hydrogen economy’.

Catalytic decomposition of dibenzothiophene sulfone over K-based oxides supported on alumina

K2O/Al2O3 catalyst could exhibit a superior conversion of sulfones at a lower reaction temperature. Meanwhile, the conversion of sulfones was linearly correlated with the logarithm of the total basic sites of the catalyst.

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 N2. The MgAlO catalyst had high total basic sites and high total acid sites that were crucial for ethanol Guerbet reaction. The MgAlO catalyst showed the highest butanol selectivity at 300℃ under WHSV = 3.10 h-1 and nitrogen flow rate = 3,600 mL/h, and the highest butanol yield at 400℃ under WHSV = 3.10 h-1 and nitrogen flow rate = 900 mL/h. It can be summarized that in order to enhance the butanol yield, the low WHSV is preferred to increase the contact time of ethanol and catalyst under moderate temperature.

The effect of NaF amount on solid base catalysts derived from F-Ca-Mg-Al layered double hydroxides and dimethyl carbonate synthesis

Versatile and environmentally benign dimethyl carbonate (DMC) synthesized by propylene carbonate (PC) and methanol via transesterification is green and energy efficient. A series of solid base catalysts derived from F-Ca-Mg-Al layered double hydroxides (LDHs) with different NaF amount were prepared, characterized and tested for the transesterification reaction. The properties of the catalysts modified by fluorine have improved obviously. The catalytic activity increases in the order of: FCMA-0.8 > FCMA-0.4 > FCMA-1.2 > FCMA-1.6 > FCMA-0, which is consistent with the total basic sites amount and the strong basic sites amount. FCMA-0.8 has the best catalytic activity as pure CaO catalyst, and the PC conversion, DMC selectivity and DMC yield are 66.8%, 97.4% and 65.1%, respectively. Furthermore, the DMC yield for FCMA-0.8 just decreased 3.9% (33.2% for CaO catalyst) after 10 recycles. FCMA-0.8 has good prospects in the transesterification of PC with methanol to DMC for industrial application.

COx-free hydrogen production from ammonia at low temperature using Co/SiC catalyst: Effect of promoter

Cobalt catalysts (5 wt%) using β-SiC as a support and modified with different alkaline (K and Cs), alkaline-earth (Ca and Mg) and rare-earth (La and Ce) metals were prepared, characterized, and examined in the hydrogen production from ammonia decomposition at low temperatures. Porous SiC has been proved to be a suitable support for promoted cobalt catalysts, which are highly active for the target decomposition reaction. Catalysts modified with small amount (1 wt%) of K and La remarkably enhanced the catalytic activity whereas the addition of Cs, Mg, Ca or Ce to cobalt catalyst decreased the ammonia conversion with respect to the unpromoted catalyst. The total basic sites and electron-donor properties of the K metal modified the electronic structure of cobalt active sites increasing the ammonia conversion at low temperatures. However, an excess of K promoter resulted in a decrease in the hydrogen production due to the blockage of the active sites. Therefore, the catalyst containing 1 wt% K and 5 wt% Co resulted in an excellent H2 production associated with an ammonia conversion close to 100% at 450 °C. Moreover, the selected catalyst provided suitable performance stability after one day of reaction.

Highly active and durable Ca-based solid base catalyst for biodiesel production

Calcium-based (Ca-based) oxides are promising candidates to replace sodium or potassium hydroxide as base catalysts in transesterification for biodiesel production, owe to their high activity and recyclability. However, their readily leaching in the reaction process is the main reason for its low reusability. This problem has long been the bottleneck of heterogeneous catalytic transesterification for biodiesel production. To solve this problem, we employed a solid-state synthesis approach to fabricate the Ca-based solid base catalyst, which showed extraordinarily high activity and stability for biodiesel synthesis. The catalyst, named NCS, could achieve up to 98.0% biodiesel (fatty acid methyl esters, FAMEs) yield in 1 h at 90 °C with 5 wt% of catalyst loading. The catalyst can be reused 26 times with a biodiesel yield of at least 90.0%. With thorough characterization, we found that the extraordinary performance of the catalyst owes to the strong basic sites and its anti-carbonation ability. The strong basic sites, formed by the coordination between O, Na, Si, and Ca, can also moderate the leaching of Ca-related basic sites into the reaction medium. Performance reduction of NCS could be attributed to the shift of strong basic sites to weaker ones without significant loss of total basic sites. Above all, we believe that the NCS catalyst is a promising catalyst for large-scale biodiesel production.

Contributions of acidic-basic sites on hybridized FER@g-C3N4 for liquid-phase decarboxylation of naphthenic acids

The efficient removal method of acidic and corrosive organic naphthenic acids (NAs) in heavy crude oils such as benzoic acid as a model acidic component was investigated for a liquid-phase decarboxylation reaction. A novel hybridized heterogeneous basic graphitic carbon nitride (g-C3N4) coated on the acidic ferrierite (H-FER) zeolite (denoted as FER@CN) was newly proposed as one of the efficient heterogeneous hybridized catalysts. The basic g-C3N4 selectively promoted the absorption of the acidic NAs by acid-base neutralization reaction, and the acidic H-FER effectively enhanced decarboxylation rate by generating CO2. The synergy effects of the hybrid FER@CN were maximized at an optimal g-C3N4/FER weight ratio of 0.5 by enhancing the number of the moderate strength acidic and total basic sites simultaneously. The promoting effects between acidic and basic sites on the FER@CN were mainly attributed to a higher dispersion of g-C3N4 nanoparticles on the H-FER surfaces, which was responsible for a higher decarboxylation activity with larger reduction of total acid number (TAN) with the help of the larger amount of moderate strength acidic and basic sites.

NiLaM (M = Ce and/or Zr) mixed oxide catalysts for synthesis gas production by biogas reforming processes

NiLaM (M = Ce and/or Zr) catalysts were prepared by the polymerized complex method and evaluated in the dry, oxidative dry, and tri-reforming of a synthetic biogas (CH4/CO2 = 1.5) at 800 °C and atmospheric pressure. The catalysts that possessed the highest number of total basic sites and stronger Ni-support interaction showed better activity and coke resistance. A lower level of carbon deposits, with higher reactivity, was found for these catalysts in tri-reforming experiments. However, catalyst deactivation was observed for NiLaCe, attributed to nickel re-oxidation.

The effect of adsorbed oxygen species on carbon-resistance of Ni-Zr catalyst modified by Al and Mn for dry reforming of methane

Dry reforming of methane was investigated over Ni-Zr catalysts modified by Aluminum and Manganese. The catalysts were characterized by XRD, CO2-TPD, XPS, TGA, and Raman. Among all prepared catalysts, the 5Al-5 Mn (5 wt% Al and 5 wt% Mn) catalyst showed the highest CH4 and CO2 conversion at 700 °C DRM with low carbon deposition. The CO2-TPD results exhibited that the 5Al-5 Mn catalyst had the highest amounts of both total basic sites and medium-strength basic sites, which could promote the adsorption and activation of CO2 molecule during the DRM reaction, and further reduce the carbon deposition. The XRD results suggested that the addition of both Al and Mn led to smaller nickel particle size. Besides, the lower carbon deposition on 5Al-5Mn and 2.5Al-7.5Mn catalyst was derived from a higher content of surface adsorption oxygen species, which was verified by the O 1s results. While the lower number of basic sites, more strong basic sites and larger particle size on 5Mn and 5Al catalysts result in a higher amount of carbon deposition.

Aldol condensation reaction of acetone on MgO nanoparticles surface: An in-situ drift investigation

Acetone adsorption and catalytic interactions with a MgO nanoparticle surface was studied using in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) at room temperature. Acetone showed adsorption bands at 2965, 1717, 1597, 1422, 1415, 1367, 1238, 1229, and 1204 cm−1. The MgO was found to be a good catalyst for the activation of the aldol condensation reaction of acetone to form di-acetonealcohol (DAA). The OH group role on the MgO surface was found to be a suppression agent to the further dehydration of DAA to mesityl oxide. This is probably because the OH group blocks the active sites on the MgO surfaces that adsorbed the water formed from the dehydration of DAA. This conclusion was confirmed by identifying the basic site concentrations on MgO surface using DRIFTS and TPD studies of CO2 adsorption/desorption on MgO nanoparticles surface. The high-strength basic sites which are required to dehydrate DDA to mesityl oxide was found to represent only 17.5 % of the total basic site concentration, while the low-strength basic sites resulted from hydroxyl surface group represent 22.5 %. On the other hand, the acetone interaction with the MgO surfaces produced several components such as formaldehyde, acetate, ethoxide, as well as other carbonate species such as bicarbonate, bidentate carbonate, and monodentate carbonate. The results of the present investigation supply important essential insights into catalytic reactions resulted from acetone adsorption on MgO nanoparticle surfaces.

Datasets on process transesterification of binary blend of oil for fatty acid ethyl ester (FAEE) synthesized via the ethanolysis of heterogeneous doped catalyst.

The data employed the blend of waste used oil and beef tallow for the synthesis of fatty acid ethyl ester (FAEE) via ethanolysis of developed catalyst from calcined fermented cocoa pod husk powder (CFCPHP) doped with burnt cocoa pod husk powder (BCHP). Characterization of the developed doped catalyst (DDC) was carried out using FTIR, SEM, XRD, and BET adsorption analysis, while the basic strength of the DDC was tested through reusability test data. Mathematical optimization of the process condition was carried out through Box-Behnken Experimental Design (BBED) in 29 runs with variations in four variables as catalyst concentration (1.5 to 3.5 wt.%), reaction time (60 to 100 min), ethanol/oil molar ratio (EtOH/OMR) of 3 to 7, and reaction temperature (60 to 80 °C). The FAEE quality was ascertained by determining its fuel properties.The data showed that the binary blend ratio of 42:58 of Waste Used oil: Beef Tallow oil (WUO: BTO) was obtained through API gravity ratio formulation. The developed doped catalyst (DDC) produced a high CaO-base of 84.30 (wt.%), with a high total basic site of 210 μmole.g−1 via BET and XRD analysis. The SEM analysis dataset showed non-uniform sizes, highly porous and crystalline sample, while the dataset on FTIR analysis data confirmed the presence of wagging and twisting CO32−, the bending vibration of O—Ca-O, the sp2 of C = O, C = C, the sp of C ≡ C and C ≡ N, the bending structure of O—H, and the O=O, N ≡ O of Amines, and Amides. Based on the experiment, the maximum experimental yield of 97.80 (%wt.) at runs 7, and low yield of 89.50 (%wt.) at run 17 was obtained for FAEE. Mathematical optimization in 10 solutions predicted the FAEE yield of 97.7999 (%wt.) at the catalyst concentration of 3.10 (wt.%), the reaction time of 68.09 min, the EtOH/OMR of 3.01, and the reaction temperature of 72.21 °C. This data was validated in replicate, and the average mean value of FAEE was 97.68 (%wt.). Dataset on ANOVA and parametric analysis showed that the variable factors considered were significant at p-value <0.0001, with high R2 of 99.14%, R2-predicted of 98.32%, R2-adjusted of 98.28%, and adequate precision of 51.152, respectively. Catalyst reusability test data showed that the cycle number was stopped at the 5th cycle due to the decrease in catalyst basic strength. The produced FAEE dataset was within the recommended standard, and the data showed the developed doped catalyst successfully converted binary blend oil to FAEE, and the fermentation process increased the CaO-based conversion of DDC.

Application of carbon nanotubes prepared from CH4/CO2 over Ni/MgO catalysts in CO2 capture using a BEA–AMP bi-solvent blend

Abstract Carbon nanotubes (CNTs) were synthesized by the chemical vapour deposition of methane and carbon dioxide over a Ni/MgO catalyst. The synthesized CNTs were then mixed with K/MgO catalyst at different ratios and used as the catalyst for CO2 absorption in butylethanolamine-2-amino-2-methyl-l-propanol bi-solvent blend. The catalysts were characterized using X-ray diffraction, scanning electron microscopy, butylethanolamine, thermal gravimetric analysis and temperature-programmed desorption of carbon dioxide in order to determine the characteristics responsible for good CO2-absorption performance. The results showed that, with the addition of a catalyst into the amine solution, the amine reached equilibrium CO2 loading faster than without a catalyst. Also, the increase in the CNT content of the KMgO/CNTs catalyst made the CO2 absorption reach equilibrium much more quickly compared with just KMgO alone and without a catalyst. The KMgO/CNTs at a ratio of 1:4 yielded the fastest time to reach CO2-loading equilibrium at 240 min, which was mainly due to the increase in strong basic sites as well as the highest total basic sites with an increase in CNT content. In addition, because of the extremely large specific surface area and pore volume generated due to the CNT, the number of exposed active centres per unit mass increased tremendously, leading to a corresponding tremendous increase in CO2 absorption.

CHARACTERIZATION AND BEHAVIOUR OF PT CATALYSTS SUPPORTED ON BASIC MATERIALS IN DRY REFORMING OF METHANE

ABSTRACT Different basic materials, such as K-L zeolite, K-Al2O3, K-Mg/Al mixed oxide and MgO, were used as supports of Pt-catalysts for the dry reforming of methane (DR) reaction. The effects of the distribution of basic strength in the support on the metal-support properties and catalyst performance were evaluated. The density of strong and the total basic sites decreased as follows: MgO>K(Mg-Al) >K-Al2O3>K-L. The total basic sites decrease from 214 to 23 µmol CO2. g-1, for MgO and KL, respectively. Pt catalysts supported on materials with high density of strong basic sites such as MgO were the most adequate for the DR reaction. An increase in the dehydrogenation velocity of 12.1 to 25.2 mol h-1 g-1 was observed between Pt/KL and Pt/MgO, which indicates a higher metallic dispersion of the latter catalyst. With respect to the DR reaction, both catalysts have a similar CO2 conversion, but the CH4 conversion and the H2/CO ratio increase from 71.1 to 83.0 % and 0.5 to 0.73, respectively. The best catalytic behaviour of Pt/MgO would be related with the good interaction between the metal and the basic support. The methane conversion and the H2/CO ratios obtained by DR reaction correlate quite well with the basicity of the different catalysts.

Methanol synthesis from CO2 hydrogenation over CuO-ZnO-ZrO2-MxOy catalysts (M=Cr, Mo and W)

Three CuO-ZnO-ZrO2-MxOy (CZZM, M = Cr, Mo and W) mixed oxides were prepared by a co-precipitation method and tested as catalysts for methanol synthesis from CO2 hydrogenation. The catalysts were characterized by XRD, N2 adsorption/desorption, XPS, reactive N2O adsorption, H2-TPR, and CO2-TPD techniques. The results indicated that the methanol selectivity and yield of the CuO-ZnO-ZrO2 catalyst noticeably increased by the additions of MoO3 and WO3, but slightly decreased by Cr2O3 doping. Combining with the characterization results, the difference in methanol yield over the three catalysts can be attributed to the differences in their BET specific surface areas (SBET) and adsorption capacities for CO2, while the methanol selectivity is closely correlated to the ratio of surface contents of Zn to Cu, as well as the fraction of strong basic sites in the total basic sites of the investigated catalysts.

Ce- and Y-Modified Double-Layered Hydroxides as Catalysts for Dry Reforming of Methane: On the Effect of Yttrium Promotion

Ce- and Y-promoted double-layered hydroxides were synthesized and tested in dry reforming of methane (CH4/CO2 = 1/1). The characterization of the catalysts was performed using X-ray fluorescence (XRF), X-ray diffraction (XRD), N2 sorption, temperature-programmed reduction in H2 (TPR-H2), temperature-programmed desorption of CO2 (TPD-CO2), H2 chemisorption, thermogravimetric analysis coupled by mass spectrometry (TGA/MS), Raman, and high-resolution transmission electron microscopy (HRTEM). The promotion with cerium influences textural properties, improves the Ni dispersion, decreases the number of total basic sites, and increases the reduction temperature of nickel species. After promotion with yttrium, the increase in basicity is not directly correlated with the increasing Y loading on the contrary of Ni dispersion. Dry reforming of methane (DRM) was performed as a function of temperature and in isothermal conditions at 700 °C for 5 h. For catalytic tests, a slight increase of the activity is observed for both Y and Ce doped catalysts. This improvement can of course be explained by Ni dispersion, which was found higher for both Y and Ce promoted catalysts. During DRM, the H2/CO ratio was found below unity, which can be explained by side reactions occurrence. These side reactions are linked with the increase of CO2 conversion and led to carbon deposition. By HRTEM, only multi-walled and helical-shaped carbon nanotubes were identified on Y and Ce promoted catalysts. Finally, from Raman spectroscopy, it was found that on Y and Ce promoted catalysts, the formed C is less graphitic as compared to only Ce-based catalyst.

Biodiesel production by ethanolysis of palm oil using SrO as a basic heterogeneous catalyst

In this study, SrO was used as a solid catalyst for simple conversion of palm oil to biodiesel production via the ethanolysis reaction. This catalyst has a high basic strength (H_) and a total basic site of about 3725 μmol/g. The results showed that under optimum reaction conditions at catalyst loading amount of 5 wt.%, ethanol/oil molar ratio of 12:1 and reaction temperature 80 °C; 98.2% yield of fatty acid ethyl ester (FAEE or biodiesel) could be achieved in 3 h. The SrO catalyst can be reused for at least 5 times with excellent catalytic activity without regeneration or treatment. The obtained biodiesel product after purification and treatment process shows high quality fuel properties according to ASTM D6751 and EN 14214 standards for bio-auto fuels. The results indicated that transesterification of palm oil with ethanol using SrO as a basic heterogeneous catalyst is a commercially viable way for biodiesel production in the industrial scale.