Zirconia catalysts (ZrO2 and Na-ZrO2) for the conversion of phenethyl phenyl ether (PPE) in supercritical water

Eom, Hee Jun; Kim, Min Sung; Lee, Dae Won; Hong, Yoon Ki; Jeong, Gwangsik; Lee, Kwan Young

doi:10.1016/j.apcata.2014.12.052

Cited by 26 publications

(18 citation statements)

References 38 publications

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“…Alternatively, the impregnation with 1% Mg resulted in an increased CO 2 chemisorption quantity and increased basic site density. The 1%Na/ZrO 2 -873 K sample could not be evaluated due to technical limitations; however the samples loaded with 0.01% and 0.1% Na show an increase in CO 2 chemisorption, in accordance with previous results (Eom et al 2015;Kozlowski and Davis 2013;Liu et al 2007).…”

Section: Co 2 Chemisorption Analysissupporting

confidence: 87%

“…Samples calcined at 673 K had peaks of both tetragonal and monoclinic structures, however, the low intensity and large width of the peaks indicates that no phase is well defined and that the crystal sizes were small. Measurements of the crystallite size using the Scherrer Equation on the 2θ = 28.5° peak (Eom et al 2015;Kumar et al 2015;Mekhemer 1998) resulted in 7, 20 and 26 nm for the samples calcined at 673, 873 and 1073 K, respectively. For samples calcined at 873 K, there is a clear predominance of the monoclinic structure with a small tetragonal peak.…”

Section: Xrd Analysismentioning

confidence: 99%

“…Zirconium oxide has both weak acid and basic sites (Tomishige et al 2000), and the acid and basic characteristics of ZrO 2 solids can be easily manipulated by incorporating an external component. Basic site concentration was found to increase by treating ZrO 2 with NaOH (Eom et al 2015;Liu et al 2007) and by impregnating ZrO 2 with Na ions (Kozlowski and Davis, 2013) or Mg ions (Sun et al 2011). In addition, Mg-modified ZrO 2 was found to have increased CO 2 adsorption between 373 and 473 K (Liu et al 2005), which made Mg/ZrO 2 an interesting catalyst for DMC production from methanol and CO 2 (Romero et al 2011).…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of diethyl carbonate from ethanol and CO2 over ZrO2 catalysts

Denardin

Valença

2020

Braz. J. Chem. Eng.

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Diethyl carbonate (DEC) is a versatile chemical with several commercial uses. The synthesis of DEC from carbon dioxide and ethanol is both environmentally friendly and can be integrated into the ethanol biorefinery. A thermodynamic evaluation was made to predict the amount of DEC produced at equilibrium at the reaction conditions used in this work. Zirconium oxide solids were prepared using sol-gel methodology and were loaded with Na, Mg or PO 4 −3 using the incipient wetness impregnation method. Catalytic tests were carried out in a 500 mL stainless steel Parr reactor at 423 K. The DEC yield decreased as the Na or Mg load increased, while increasing the yield of acetaldehyde. However, DEC yield and selectivity increased as the PO 4 −3 load increased, while the acetaldehyde yield decreased. Lower overall acid site density and lower than 2.8 µmol-CO 2 /m 2 basic site density resulted in a higher DEC yield. Keywords Ethanol • CO 2 • Diethyl carbonate • Zirconia List of symbols C p Specific heat (kJ mol −1 K −1) ∆ r C p Specific heat of the reaction (kJ mol −1 K −1) D BJH BJH desorption diameter (nm) ∆G o f,i Gibbs free energy of formation (kJ mol −1) ∆ r G o 298 Reaction Gibbs free energy at 298 K (kJ mol −1) ∆ r G o T Reaction Gibbs free energy at temperature T (kJ mol −1) ∆H o f,i Standard formation enthalpy (kJ mol −1) ∆ r H o 298 Reaction enthalpy at 298 K (kJ mol −1) ∆ r H o T Reaction enthalpy at temperature T (kJ mol −1) v i Stoichiometric coefficients K eq Reaction equilibrium constant (cm 3 mol −1) p v Pore volume (cm 3 g −1) R Universal gas constant (kJ mol −1 K −1) [EtOH] 0 Ethanol concentration in the liquid phase (mol L −1) S BET B.E.T. surface area (m 2 g −1) V l liquid Molar volume (cm 3) V g gas Molar volume (cm 3) V t Total pore volume (cm 3) Greek letters λ X-ray wavelength (nm) 2θ Incidence peak angle in XRD (o)

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Section: Co 2 Chemisorption Analysissupporting

confidence: 87%

Section: Xrd Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Synthesis of diethyl carbonate from ethanol and CO2 over ZrO2 catalysts

Denardin

Valença

2020

Braz. J. Chem. Eng.

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“…Acid site loadings and corresponding densities are shown in Table 1, and reveal that calcination increases the total acid site density (due to vacancy formation) from 2.5→4.0 µmol.m - 2 , associated with the emergence of weak acid sites ( Figure S7). The presence of weak and strong acid sites on ZrO 2 has previously been suggested by NH 3 -TPD, which shows only a poorly resolved doublet desorption peak, 63 and also by using potentiometric titration. 61 While the strength of the weak acid sites remains unchanged with calcination temperature, the stronger acid sites are observed to weaken with progressive recrystallization of ZrO 2 , evidenced by an increase in the desorption temperature of reactively-formed propene.…”

Section: Journal Name Articlementioning

confidence: 67%

Zirconia catalysed acetic acid ketonisation for pre-treatment of biomass fast pyrolysis vapours

Jahangiri

Osatiashtiani

Bennett

et al. 2018

Catal. Sci. Technol.

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“…The interval between 40 and 170 °C corresponds to weak basic sites. 32 The TG/derivative thermogravimetry (DTG) curves (Fig. S1(c)) depicted five main mass-loss events.…”

Section: Characterization Of Tpc7mentioning

confidence: 99%

Tangerine peel ashes applied as green catalyst: a biorefinery‐based approach for biodiesel production

Oliveira

Lima

Moura

et al. 2021

Biofuels Bioprod Bioref

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In this research, a greener heterogeneous catalyst (named TPC) was obtained from 'Ponkan' tangerine (Citrus reticulata Blanco) peel ashes. TPC was efficient for biodiesel production through the methyl route using refined soybean oil and waste cooking oil as raw materials in a biorefinerybased approach. Eight catalyst samples were prepared via calcination of the ashes at 700 °C (TPC7), 800 °C (TPC8) and 900 °C (TPC9), and blends of TPC7 with CaCO 3 and K 2 CO 3 . All the catalysts were employed in preliminary tests for the transesterification reactions. A set of characterization techniques such as Fourier transform infrared and spectroscopy, X-ray diffractometry, X-ray fluorescence, field emission gun scanning electron microscopy, energy-dispersive X-ray, CO 2 -desorption at programmed temperature, thermogravimetric analysis/derivative thermogravimetry (DTG), N 2 adsorption-desorption isotherms, and the Hammett basicity test were performed for catalysts assessment. The X-ray diffractometry patterns showed peaks associated with characteristic phases of K 2 CO 3 , CaCO 3 , K 2 Ca(CO 3 ) 2 , MgO and CaO, confirmed by Fourier transform infrared spectroscopy spectroscopy and X-ray fluorescence. CO 2 -desorption at programmed temperature data demonstrated the presence of basic sites in the TPC catalysts. The experimental evaluation by response surface methodology using the D-Optimal design showed that the reaction time effect (F = 19.04, P-value = 0.0005) and its interaction with the molar ratio effect are the most significant parameters to improve the yield of refined soybean oil biodiesel. The selected reaction conditions promoted a methyl ester conversion higher than 92%, as calculated from 1 H NMR data. Furthermore, the production of waste cooking oil biodiesel was effective using TPC7 and TPC8 catalysts, allowing a sustainable and economic feasibility process.

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Zirconia catalysts (ZrO2 and Na-ZrO2) for the conversion of phenethyl phenyl ether (PPE) in supercritical water

Cited by 26 publications

References 38 publications

Synthesis of diethyl carbonate from ethanol and CO2 over ZrO2 catalysts

Synthesis of diethyl carbonate from ethanol and CO2 over ZrO2 catalysts

Zirconia catalysed acetic acid ketonisation for pre-treatment of biomass fast pyrolysis vapours

Tangerine peel ashes applied as green catalyst: a biorefinery‐based approach for biodiesel production

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