ORCID Profile
0000-0002-9864-3332
Current Organisation
Aston University
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Publisher: Wiley
Date: 15-02-2017
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7RE00162B
Abstract: Lipase immobilised on silica monoliths has been prepared and applied as biocatalytic continuous-flow microreactors for the transesterification of tributyrin as a model bio-oil component.
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4GC01139B
Abstract: A simple grafting protocol is reported affording a ten-fold enhancement in acid site density of mesoporous sulfonic acid silicas compared to conventional syntheses.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA01867K
Abstract: Hierarchical porous catalysts offer highly connected architectures for enhanced transport of bulky molecules and the sustainable manufacturing of bio-derived platform chemicals and fuels.
Publisher: Springer Science and Business Media LLC
Date: 09-11-2020
Publisher: MDPI AG
Date: 18-12-2018
DOI: 10.3390/CATAL8120667
Abstract: Zn–Al layered double hydroxides (LDHs) of general formula [Zn2+(1−x)Al3+x(OH)2]x+(CO32−)x/2·yH2O are promising solid base catalysts for the transesterification of lipids to biofuels. However, conventional synthetic routes employ alkali hydroxide/carbonate precipitants which may contaminate the final LDH catalyst and biofuel. The use of (NH3)2CO3 and NH3OH as precipitants affords alkali-free Zn–Al-LDHs spanning a wide composition range. The hydrothermal reconstruction of calcined Zn–Al-LDHs offers superior solid basicity and catalytic activity for the transesterification of C4–C18 triglycerides with methanol, compared with cold liquid phase or vapour phase reconstruction. Hydrothermally activated Zn3.3–Al-LDH was stable towards leaching during transesterification.
Publisher: Elsevier BV
Date: 10-2018
Publisher: Wiley
Date: 13-03-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3CY00902E
Abstract: Mg–Al hydrotalcite coatings have been grown on alumina via a novel alkali- and nitrate-free impregnation route and subsequent calcination and hydrothermal treatment.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5GC01889G
Abstract: Propylsulfonic acid derivatised SBA-15 catalysts exhibit excellent catalytic performance and water tolerance for the upgrading of a model pyrolysis bio-oil via acetic acid esterification with benzyl alcohol in toluene.
Publisher: MDPI AG
Date: 03-03-2022
Abstract: NiAl layered double hydroxides (LDHs) are promising bifunctional catalysts comprising tunable redox and Lewis acidic sites. However, most studies of NiAl LDH employ alkali hydroxide carbonate precipitants which may contaminate the final LDH catalyst and leach into reaction media. Here, we report an alkali-free route to prepare NixAl LDHs with a composition range x = 1.7 to 4.1 using (NH4)2CO3 and NH4OH as precipitants. Activation of LDHs by calcination–rehydration protocols reveal NixAl LDHs can be reconstructed under mild hydrothermal treatment (110 °C for 12 h), with the degree of reconstruction increasing with Ni content. Catalyst activity for tributyrin transesterification with methanol was found to increase with Ni content and corresponding base site loadings TOFs also increased, suggesting that base sites in the reconstructed LDH are more effective for transesterification. Hydrothermally reconstructed Ni4.1Al LDH was active for the transesterification of C4–C12 triglycerides with methanol and was stable towards leaching during transesterification.
Publisher: Wiley
Date: 06-02-2018
Abstract: Chemo- and regioselectivity in a heterogeneously catalyzed cross aldol reaction were directed by tuning the nature of the sites, textural properties, and reaction conditions. Catalysts included sulfonic acid-functionalized resins or SBA-15 with varying particle size or pore diameter, H-BEA zeolites, and Sn-BEA zeotype conditions were 25 °C to 170 °C in organic media. Benzaldehyde and 2-butanone yielded branched (reaction at -CH
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6GC01089J
Abstract: Sulfated zirconia in pure and highly dispersed form is a tunable and effective solid acid catalyst for the batch and continuous liquid phase esterification of carboxylic acids.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4GC01689K
Abstract: Conformal hydrotalcite coatings over hierarchically-ordered SBA-15 exhibit exceptional activity for transesterification of bulky triglycerides.
Publisher: Wiley
Date: 22-11-2017
Publisher: Springer Science and Business Media LLC
Date: 26-10-2020
Publisher: MDPI AG
Date: 10-01-2019
DOI: 10.3390/MOLECULES24020239
Abstract: The catalytic deoxygenation of bio-based feedstocks to fuels and chemicals presents new challenges to the catalytic scientist, with many transformations either performed in or liberating water as a byproduct during reaction. The design of catalysts with tunable hydrophobicity to aid product and reactant adsorption or desorption, respectively, is vital for processes including (trans)esterification and condensation reactions employed in sustainable biodiesel production and bio-oil upgrading processes. Increasing surface hydrophobicity of catalyst materials offers a means to displace water from the catalyst active site, and minimizes potential deactivation or hydrolysis side reactions. Hybrid organic–inorganic porous solids offer exciting opportunities to tune surface polarity and hydrophobicity, as well as critical parameters in controlling adsorption, reactant activation, and product selectivity in liquid and vapor phase catalysis. Here, we review advances in the synthesis and application of sulfonic-acid-functionalized periodic mesoporous organosilicas (PMO) as tunable hydrophobic solid acid catalysts in reactions relevant to biorefining and biofuel production.
Publisher: Elsevier BV
Date: 03-2020
Publisher: MDPI AG
Date: 28-05-2018
DOI: 10.3390/CATAL8060228
Publisher: Wiley
Date: 16-08-2017
Publisher: Springer Science and Business Media LLC
Date: 03-06-2020
DOI: 10.1186/S13068-020-01735-7
Abstract: Platform chemicals are essential to industrial processes. Used as starting materials for the manufacture of erse products, their cheap availability and efficient sourcing are an industrial requirement. Increasing concerns about the depletion of natural resources and growing environmental consciousness have led to a focus on the economics and ecological viability of bio-based platform chemical production. Contemporary approaches include the use of immobilized enzymes that can be harnessed to produce high-value chemicals from waste. In this study, an engineered glucose dehydrogenase (GDH) was optimized for gluconic acid (GA) production. Sulfolobus solfataricus GDH was expressed in Escherichia coli. The K m and V max values for recombinant GDH were calculated as 0.87 mM and 5.91 U/mg, respectively. Recombinant GDH was immobilized on a hierarchically porous silica support (MM-SBA-15) and its activity was compared with GDH immobilized on three commercially available supports. MM-SBA-15 showed significantly higher immobilization efficiency ( 98%) than the commercial supports. After 5 cycles, GDH activity was at least 14% greater than the remaining activity on commercial supports. Glucose in bread waste hydrolysate was converted to GA by free-state and immobilized GDH. After the 10th reuse cycle on MM-SBA-15, a 22% conversion yield was observed, generating 25 gGA/gGDH. The highest GA production efficiency was 47 gGA/gGDH using free-state GDH. This study demonstrates the feasibility of enzymatically converting BWH to GA: immobilizing GDH on MM-SBA-15 renders the enzyme more stable and permits its multiple reuse.
Publisher: Trans Tech Publications, Ltd.
Date: 04-2019
DOI: 10.4028/WWW.SCIENTIFIC.NET/SSP.290.168
Abstract: A facile, rapid, and noninvasive method for reconstructing ZnAl layered double hydroxide (LDH) is reported. ZnAl LDH series were synthesized at different Zn 2+ /Al 3+ atomic ratio (1.5-4) via an alkali-free method and reconstructed under hydrothermal route (HTM) for the first time. Fresh Zn/Al LDHs were activated at 300°C and reconstructed under hydrothermal process. A better insight and correlation study between the physiochemical properties of reconstructed ZnAl LDH in terms of their crystallinity, surface area and basicity also will be gained here. BET surface area of rehydrated s les increased up to 355 m 2 /g (Zn:Al ratio 3:1). CO 2 -TPD probed high number of basic sites density (0.1 mmol/g).
Publisher: Elsevier BV
Date: 11-2018
Publisher: Springer Science and Business Media LLC
Date: 05-04-2017
DOI: 10.1007/S13399-017-0254-X
Abstract: A family of faujasite (FAU) zeolites with different Si:Al ratio, and/or hierarchical porosity introduced via post-synthetic alkaline desilication treatment, have been evaluated as solid acid catalysts for esterification pretreatments of pyrolysis bio-oil components. Acetic acid esterification with aliphatic and aromatic alcohols including methanol, anisyl alcohol, benzyl alcohol, p -cresol and n -butanol was first selected as a model reaction to identify the optimum zeolite properties. Materials were fully characterised using N 2 porosimetry, ICP, XRD, XPS, FT-IR, pyridine adsorption, NH 3 TPD, In-situ ATR and inverse gas chromatography (IGC). IGC demonstrates that the surface polarity and hence hydrophobicity of FAU decreases with increased Si:Al ratio. Despite possessing a higher acid site loading and acetic acid adsorption capacity, high Al-content FAU possess weaker acidity than more siliceous catalysts. Esterification activity increases with acid strength and decreasing surface polarity following the order FAU30 FAU6 FAU2.6. The introduction of mesoporosity through synthesis of a hierarchical HFAU30 material further enhances esterification activity through improved acid site accessibility and hydrophobicity. Methanol was the most reactive alcohol for esterification, and evaluated with HFAU30 for the pretreatment of a real pyrolysis bio-oil, reducing the acid content by 76% under mild conditions.
Publisher: Springer Science and Business Media LLC
Date: 08-2018
DOI: 10.1557/ADV.2018.347
Publisher: American Chemical Society (ACS)
Date: 20-12-2018
Publisher: Springer Science and Business Media LLC
Date: 10-06-2015
Location: United Kingdom of Great Britain and Northern Ireland
Location: India
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Dr. Jinesh C. Manayil.