12-Tungstophosphoric acid-encapsulated metal-organic framework UiO-66: A promising catalyst for the esterification of acetic acid with n-butanol

Ma, Tianlin; Liu, Daojun; Liu, Zheng; Xu, Jinfeng; Dong, Yujing; Chen, Gangling; Liu, Yang

doi:10.1016/j.jtice.2022.104277

Cited by 19 publications

(10 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, the increase in relative intensity in the composite (Cu-BTC_PMA) compared with the parent MOF (Cu-BTC) was observed and may be due to high crystallinity which was previously reported by Zhang et al 89 Thermal gravimetric analysis (TGA) (Figure S20b) showed that the thermal stability of composite catalyst (Cu-BTC_PMA) was found to be superior to that of the parent MOF (Cu-BTC). 60,90,91 This may be due to the enhancement of crystallinity in the Cu-BTC_PMA catalyst after the incorporation of PMA in the Cu-BTC framework which is also supported by the PXRD results.…”

Section: ■ Results and Discussionmentioning

confidence: 80%

Elucidation of Active Sites and Mechanistic Pathways of a Heteropolyacid/Cu-Metal–Organic Framework Catalyst for Selective Oxidation of 5-Hydroxymethylfurfural via Ex Situ X-ray Absorption Spectroscopy and In Situ Attenuated Total Reflection-Infrared Studies

et al. 2023

View full text Add to dashboard Cite

Chemoselective oxidation of 5-hydroxymethylfurfural (HMF) over nonnoble metals to produce a bioplastic monomer, 2,5-furandicarboxylic acid (FDCA), under alkaline-free conditions is challenging and worthy of investigation. HMF oxidation into FDCA involves the concurrent oxidation of primary alcohol and an aldehyde functional group into carboxylic groups, which therefore demand a bifunctional catalyst containing dual active sites and chemoselective oxidation of HMF. The present work demonstrated the formation of new selective active sites in a composite porous material (Cu-BTC_PMA) that consists of Cu-BTC (metal−organic framework (MOF)) and polyoxometalate (POM). The porous framework provides (Cu-BTC_PMA) the desired chemoselectivity, while a selective Cu metal center in Cu-BTC (MOF) and Cu−O−Mo sites functions as active sites for the concurrent oxidation of HMF into FDCA. This catalyst exhibited a HMF conversion of 89% and an FDCA selectivity of 92.3% under base-free and mild reaction conditions. In detail, X-ray absorption spectroscopy analysis demonstrated the chemical bond tuning, as well as electronic structural modulations of MOF and POM at the molecular level, which directs the formation of new synergistic interfacial active sites and charge transfer states. This phenomenon causes the generation of the unique redox environment of copper and the multiple oxidation states along with the oxygen vacancy in the Cu-BTC_PMA catalyst, which most likely behaves as active sites for base-free oxidation. A kinetics study of this reaction was followed using in situ attenuated total reflection-infrared spectroscopy, demonstrating the stabilization of the specific intermediates that lead to the formation of FDCA. Moreover, we made comparative density functional theory and quantum theory of atoms in molecules investigations on the surface interaction between the reactant (HMF) and two catalyst models of Cu-BTC and Cu-BTC_PMA to interpret quantitatively the higher catalytic activity of the Cu-BTC_PMA catalyst. The kinetics study also evaluates the rate-determining step and activation energy for the multistep oxidation reactions.

show abstract

Section: ■ Results and Discussionmentioning

confidence: 80%

Elucidation of Active Sites and Mechanistic Pathways of a Heteropolyacid/Cu-Metal–Organic Framework Catalyst for Selective Oxidation of 5-Hydroxymethylfurfural via Ex Situ X-ray Absorption Spectroscopy and In Situ Attenuated Total Reflection-Infrared Studies

et al. 2023

View full text Add to dashboard Cite

show abstract

“…The highest yield obtained was 83.6% and 88.8% when utilised 4 wt.% of glycerol-SO 3 H and glycerol-ClSO 3 H, respectively. However, yield reduction was found (73.3% and 76.5%) for the reaction of 5 wt.% catalyst loading due to mass transfer difficulty initiated for reversable reaction, as discussed by Ma et al [ 27 ]. Therefore, 3 wt.% of catalyst loading was selected for further esterification reaction.…”

Section: Resultsmentioning

confidence: 96%

“…Figure 2 displayed the evaluation of solid glycerol catalysts for acid properties by NH 3 -TPD method and the amount of total acidity strength as tabulated in Table 1 . A sharp and intense peak presented at a low-temperature range of 150–450 °C, possessing the weak Brönsted acid sites that consist of phenolic (-OH) and carboxylic groups interacted during adsorption-desorption with ammonia gas [ 27 ]. The interaction between NH 3 and SO 3 H/ClSO 3 H species demonstrated a desorption curve such as strong Brönsted acid sites that occurred at temperatures 450–700 °C, respectively [ 28 ].…”

Section: Resultsmentioning

confidence: 99%

Glycerol-Based Retrievable Heterogeneous Catalysts for Single-Pot Esterification of Palm Fatty Acid Distillate to Biodiesel

et al. 2022

View full text Add to dashboard Cite

The by-product of the previous transesterification, glycerol was utilised as an acid catalyst precursor for biodiesel production. The crude glycerol was treated through the sulfonation method with sulfuric acid and chlorosulfonic acid in a reflux batch reactor giving solid glycerol-SO3H and glycerol-ClSO3H, respectively. The synthesised acidic glycerol catalysts were characterised by various analytical techniques such as thermalgravimetric analyser (TGA), infrared spectroscopy, surface properties adsorption-desorption by nitrogen gas, ammonia-temperature programmed desorption (NH3-TPD), X-ray diffraction spectroscopy (XRD), elemental composition analysis by energy dispersive spectrometer (EDX) and surface micrographic morphologies by field emission electron microscope (FESEM). Both glycerol-SO3H and glycerol-ClSO3H samples exhibited mesoporous structures with a low surface area of 8.85 mm2/g and 4.71 mm2/g, respectively, supported by the microscopic image of blockage pores. However, the acidity strength for both catalysts was recorded at 3.43 mmol/g and 3.96 mmol/g, which is sufficient for catalysing PFAD biodiesel at the highest yield. The catalytic esterification was optimised at 96.7% and 98.2% with 3 wt.% of catalyst loading, 18:1 of methanol-PFAD molar ratio, 120 °C, and 4 h of reaction. Catalyst reusability was sustained up to 3 reaction cycles due to catalyst deactivation, and the insight investigation of spent catalysts was also performed.

show abstract

“…This is despite their high activity, solubility in many polar solvents, and very low surface area, which limit their application for catalysis. Therefore, the loading of various HPAs on Zr-based MOF materials has been performed [ 47 , 48 ].…”

Section: Zr-based Mof Catalystsmentioning

confidence: 99%

Zr-Based Metal-Organic Frameworks for Green Biodiesel Synthesis: A Minireview

et al. 2022

View full text Add to dashboard Cite

Metal–organic frameworks (MOFs) have widespread application prospects in the field of catalysis owing to their functionally adjustable metal sites and adjustable structure. In this minireview, we summarize the current advancements in zirconium-based metal–organic framework (Zr-based MOF) catalysts (including single Zr-based MOFs, modified Zr-based MOFs, and Zr-based MOF derivatives) for green biofuel synthesis. Additionally, the yields, conversions, and reusability of Zr-based MOF catalysts for the production of biodiesel are compared. Finally, the challenges and future prospects regarding Zr-based MOFs and their derivatives for catalytic application in the biorefinery field are highlighted.

show abstract

12-Tungstophosphoric acid-encapsulated metal-organic framework UiO-66: A promising catalyst for the esterification of acetic acid with n-butanol

Cited by 19 publications

References 63 publications

Elucidation of Active Sites and Mechanistic Pathways of a Heteropolyacid/Cu-Metal–Organic Framework Catalyst for Selective Oxidation of 5-Hydroxymethylfurfural via Ex Situ X-ray Absorption Spectroscopy and In Situ Attenuated Total Reflection-Infrared Studies

Elucidation of Active Sites and Mechanistic Pathways of a Heteropolyacid/Cu-Metal–Organic Framework Catalyst for Selective Oxidation of 5-Hydroxymethylfurfural via Ex Situ X-ray Absorption Spectroscopy and In Situ Attenuated Total Reflection-Infrared Studies

Glycerol-Based Retrievable Heterogeneous Catalysts for Single-Pot Esterification of Palm Fatty Acid Distillate to Biodiesel

Zr-Based Metal-Organic Frameworks for Green Biodiesel Synthesis: A Minireview

Contact Info

Product

Resources

About