Publications
75 results found
Navar R, Tarantino G, Beynon OT, et al., 2022, Tracking the solid-state incorporation of Sn into the framework of dealuminated zeolite beta, and consequences for catalyst design, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 10, Pages: 22025-22041, ISSN: 2050-7488
Botti L, Navar R, Tolborg S, et al., 2022, High-Productivity Continuous Conversion of Glucose to alpha-Hydroxy Esters over Postsynthetic and Hydrothermal Sn-Beta Catalysts, ACS SUSTAINABLE CHEMISTRY & ENGINEERING, Vol: 10, Pages: 4391-4403, ISSN: 2168-0485
Bartholomeeusen E, De Cremer G, Kennes K, et al., 2021, Optical encoding of luminescent carbon nanodots in confined spaces, CHEMICAL COMMUNICATIONS, Vol: 57, Pages: 11952-11955, ISSN: 1359-7345
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- Citations: 1
Botti L, Meier S, Hammond C, 2021, Mechanistic Studies of Continuous Glucose Upgrading over Lewis Acidic Silicates by Operando UV-Vis and HSQC NMR, ACS CATALYSIS, Vol: 11, Pages: 1296-1308, ISSN: 2155-5435
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- Citations: 6
Caiti M, Tarantino G, Hammond C, 2020, Developing a Continuous Process for Isosorbide Production from Renewable Sources, CHEMCATCHEM, Vol: 12, Pages: 6393-6400, ISSN: 1867-3880
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- Citations: 4
Botti L, Padovan D, Navar R, et al., 2020, Thermal Regeneration of Sn-Containing Silicates and Consequences for Biomass Upgrading: From Regeneration to Preactivation, ACS CATALYSIS, Vol: 10, Pages: 11545-11555, ISSN: 2155-5435
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- Citations: 10
Botti L, Kondrat SA, Navar R, et al., 2020, Solvent-Activated Hafnium-Containing Zeolites Enable Selective and Continuous Glucose-Fructose Isomerisation, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, Vol: 59, Pages: 20017-20023, ISSN: 1433-7851
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- Citations: 15
Tarantino G, Hammond C, 2020, Catalytic C(sp(3))-F bond formation: recent achievements and pertaining challenges, GREEN CHEMISTRY, Vol: 22, Pages: 5195-5209, ISSN: 1463-9262
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- Citations: 30
Botti L, Kondrat SA, Navar R, et al., 2020, Solvent-Activated Hafnium-Containing Zeolites Enable Selective and Continuous Glucose–Fructose Isomerisation, Angewandte Chemie, ISSN: 0044-8249
© 2020 Wiley-VCH GmbH The isomerisation of glucose to fructose is a critical step towards manufacturing petroleum-free chemicals from lignocellulosic biomass. Herein we show that Hf-containing zeolites are unique catalysts for this reaction, enabling true thermodynamic equilibrium to be achieved in a single step during intensified continuous operation, which no chemical or biological catalyst has yet been able to achieve. Unprecedented single-pass yields of 58 % are observed at a fructose selectivity of 94 %, and continuous operation for over 100 hours is demonstrated. The unexpected performance of the catalyst is realised following a period of activation within the reactor, during which time interaction with the solvent generates a state of activity that is absent in the synthesised catalyst. Mechanistic studies by X-ray absorption spectroscopy, chemisorption FTIR, operando UV/Vis and 1H–13C HSQC NMR spectroscopy indicate that activity arises from isolated HfIV atoms with monofunctional acidic properties.
Howard IC, Hammond C, Buchard A, 2019, Polymer-supported metal catalysts for the heterogeneous polymerisation of lactones, POLYMER CHEMISTRY, Vol: 10, Pages: 5894-5904, ISSN: 1759-9954
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- Citations: 8
Botti L, Navar R, Tolborg S, et al., 2019, Influence of Composition and Preparation Method on the Continuous Performance of Sn-Beta for Glucose-Fructose Isomerisation, Topics in Catalysis, Vol: 62, Pages: 1178-1191, ISSN: 1022-5528
The stability, activity and selectivity of various Sn-Beta catalysts are investigated to identify how the composition of the catalyst, in addition to its method of preparation, impact its ability to continuously isomerise glucose to fructose. Increasing the Sn loading in post-synthetically prepared catalysts leads to a decrease of both activity and stability. Accordingly, materials containing dilute amounts of Sn appear to be most suitable for continuous operation. Furthermore, the method of preparation has a profound impact on the overall performance of the catalyst. In fact, preparation of Sn-Beta by hydrothermal synthesis results in improvements of both activity and stability, with respect to the post-synthetic preparation of an otherwise-analogous material. The improved resistance of hydrothermal Sn-Beta is attributed, through a combination of operando UV–Vis, TPD-MS and vapour adsorption isotherms, to its greater resistance to deactivation by methanol (the reaction solvent). Complementary 119Sn CPMG MAS NMR experiments also indicate the presence of different Sn sites in the hydrothermal material, which, alongside the presence of a less adsorptive siliceous matrix, may be intrinsically less prone to solvent interaction than those present in post-synthetic Sn-Beta.
Nicolau G, Tarantino G, Hammond C, 2019, Acceptorless Alcohol Dehydrogenation Catalysed by Pd/C, CHEMSUSCHEM, Vol: 12, Pages: 4953-4961, ISSN: 1864-5631
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- Citations: 19
Caiti M, Padovan D, Hammond C, 2019, Continuous production of hydrogen from formic acid decomposition over heterogeneous nanoparticle catalysts: from batch to continuous flow, ACS Catalysis, Vol: 9, Pages: 9188-9198, ISSN: 2155-5435
We investigate the continuous generation of hydrogen via the low temperature (<110 °C), additive-free dehydrogenation of formic acid over heterogeneous Pd/C. Through a combination of kinetic (batch and continuous), spectroscopic, and mechanistic studies, we develop structure–activity–lifetime relationships for this process and in doing so reveal that a combination of pore fouling and poisoning by formate ions results in deactivation of the catalyst during continuous operation. Although these factors result in extensive deactivation in Plug Flow mode, promising results can be obtained by minimizing the steady state concentration of formic acid by operating in a continuous stirred tank reactor. In doing so, continuous operation of the system without a loss of activity for over 2500 turnovers is achieved, under mild conditions and in the absence of stoichiometric additives.
Motta D, Sanchez F, Alshammari K, et al., 2019, Preformed Au colloidal nanoparticles immobilised on NiO as highly efficient heterogeneous catalysts for reduction of 4-nitrophenol to 4-aminophenol, Journal of Environmental Chemical Engineering, Vol: 7, Pages: 103381-103381, ISSN: 2213-3437
Sanchez F, Alotaibi MH, Motta D, et al., 2018, Hydrogen production from formic acid decomposition in the liquid phase using Pd nanoparticles supported on CNFs with different surface properties, SUSTAINABLE ENERGY & FUELS, Vol: 2, Pages: 2705-2716, ISSN: 2398-4902
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- Citations: 29
Yakabi K, Jones A, Buchard A, et al., 2018, Chemoselective Lactonization of Renewable Succinic Acid with Heterogeneous Nanoparticle Catalysts, ACS SUSTAINABLE CHEMISTRY & ENGINEERING, Vol: 6, Pages: 16341-16351, ISSN: 2168-0485
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- Citations: 7
Tarantino G, Hammond C, 2018, Catalytic formation of C(sp(3))-F bonds via heterogeneous photocatalysis, ACS Catalysis, Vol: 8, Pages: 10321-10330, ISSN: 2155-5435
Due to their chemical, physical, and biological properties, fluorinated compounds are widely employed throughout society. Yet, despite their critical importance, current methods of introducing fluorine into compounds suffer from severe drawbacks. For example, several methods are noncatalytic and employ stoichiometric equivalents of heavy metals. Existing catalytic methods, on the other hand, exhibit poor activity, generality, selectivity and/or have not been achieved by heterogeneous catalysis, despite the many advantages such an approach would provide. Here, we demonstrate how selective C(sp3)–F bond synthesis can be achieved via heterogeneous photocatalysis. Employing TiO2 as photocatalyst and Selectfluor as mild fluorine donor, effective decarboxylative fluorination of a variety of carboxylic acids can be achieved in very short reaction times. In addition to displaying the highest turnover frequencies of any reported fluorination catalyst to date (up to 1050 h–1), TiO2 also demonstrates excellent levels of durability, and the system is catalytic in the number of photons required; i.e., a photon efficiency greater than 1 is observed. These factors, coupled with the generality and mild nature of the reaction system, represent a breakthrough toward the sustainable synthesis of fluorinated compounds.
Padovan D, Botti L, Hammond C, 2018, Active site hydration governs the stability of Sn-beta during continuous glucose conversion, ACS Catalysis, Vol: 8, Pages: 7131-7140, ISSN: 2155-5435
The stability of Sn-Beta for the continuous upgrading of hexoses is improved dramatically upon the addition of small amounts of water to the methanol/sugar reaction feed, despite water itself being an unfavorable solvent. Herein, the molecular level origin of this effect is investigated. Spectroscopic studies of the catalytic materials pre-, post- and during operation, with operando UV–vis, 119Sn CPMG MAS NMR, DRIFTS-MS, TGA, TPD/O-MS, and porosimetry, are coupled to additional kinetic studies, to generate detailed structure–activity–lifetime relationships. In doing so, we find that the addition of water influences two particular processes—fouling and active site modification. However, mitigating the second is the most crucial role of water. Indeed, in the absence of water, the loss of Sn–OH and Si–OH sites occurs. Notably, these changes in active site hydration correlate to deactivation and reactivation of the system. The consequences of these findings, both for mechanistic understanding of the system and to the design of alternative regeneration methods, are also discussed.
Sanchez F, Motta D, Bocelli L, et al., 2018, Investigation of the Catalytic Performance of Pd/CNFs for Hydrogen Evolution from Additive-Free Formic Acid Decomposition, C, Vol: 4, Pages: 26-26
Padovan D, Tolborg S, Botti L, et al., 2018, Overcoming catalyst deactivation during the continuous conversion of sugars to chemicals: maximising the performance of Sn-Beta with a little drop of water, Reaction Chemistry and Engineering, Vol: 3, Pages: 155-163, ISSN: 2058-9883
Producing chemicals from renewable resources represents one of the key challenges in chemical science. Whilst catalytic methods for converting renewables to chemicals offer several advantages over biological approaches, the solid catalysts developed to date are typically plagued by rapid rates of deactivation, prohibiting their greater exploitation. Here, we demonstrate, for the first time, that a Sn-containing zeolite, Sn-Beta, is capable of continuously converting saccharide solutions to value added chemicals with high levels of activity, selectivity and stability. For both the isomerisation of glucose to fructose, and the conversion of fructose to alkyl lactates, we observe that the addition of up to 10% of water to the methanol/sugar reaction feed increases reactivity by a factor of 2.5, and catalyst stability by one order of magnitude. Continuous operation for up to 1366 h (57 days) is demonstrated, with only limited loss of activity being observed over this period of time. Post-reaction characterisation indicates that the addition of water influences several elements of the catalytic system, which cooperatively result in improved performance.
Sanchez F, Motta D, Roldan A, et al., 2018, Hydrogen Generation from Additive-Free Formic Acid Decomposition Under Mild Conditions by Pd/C: Experimental and DFT Studies, Topics in Catalysis, Vol: 61, Pages: 254-266, ISSN: 1022-5528
Hammond C, Padovan D, Tarantino G, 2018, Porous metallosilicates for heterogeneous, liquid-phase catalysis: perspectives and pertaining challenges, ROYAL SOCIETY OPEN SCIENCE, Vol: 5, ISSN: 2054-5703
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- Citations: 15
Tarantino G, Hammond C, 2018, Catalytic and photocatalytic formation of C(sp3) - F bonds with heterogeneous catalysts, Chemical Sciences Journal, Vol: 09
Yakabi K, Mathieux T, Milne K, et al., 2017, Continuous Production of Biorenewable, Polymer-Grade Lactone Monomers through Sn-beta-Catalyzed Baeyer-Villiger Oxidation with H2O2, CHEMSUSCHEM, Vol: 10, Pages: 3652-3659, ISSN: 1864-5631
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- Citations: 19
Padovan D, Al-Nayili A, Hammond C, 2017, Bifunctional Lewis and Bronsted acidic zeolites permit the continuous production of bio-renewable furanic ethers, GREEN CHEMISTRY, Vol: 19, Pages: 2846-2854, ISSN: 1463-9262
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- Citations: 32
Hammond C, 2017, Intensification studies of heterogeneous catalysts: probing and overcoming catalyst deactivation during liquid phase operation, GREEN CHEMISTRY, Vol: 19, Pages: 2711-2728, ISSN: 1463-9262
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- Citations: 62
Tarantino G, Botti L, Dimitratos N, et al., 2017, Catalytic formation of C(sp(3))-F bonds via decarboxylative fluorination with mechanochemically-prepared Ag2O/TiO2 heterogeneous catalysts, RSC ADVANCES, Vol: 7, Pages: 30185-30190, ISSN: 2046-2069
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- Citations: 8
Yakabi K, Milne K, Buchard A, et al., 2016, Selectivity and Lifetime Effects in Zeolite-Catalysed Baeyer-Villiger Oxidation Investigated in Batch and Continuous Flow, CHEMCATCHEM, Vol: 8, Pages: 3490-3498, ISSN: 1867-3880
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- Citations: 14
Dimitratos N, Villa A, Prati L, et al., 2016, Effect of the preparation method of supported Au nanoparticles in the liquid phase oxidation of glycerol, Applied Catalysis A: General, Vol: 514, Pages: 267-275, ISSN: 0926-860X
Ab Rahim MH, Armstrong RD, Hammond C, et al., 2016, Low temperature selective oxidation of methane to methanol using titania supported gold palladium copper catalysts, Catalysis Science & Technology, Vol: 6, Pages: 3410-3418, ISSN: 2044-4753
<p>Selective oxidation of methane using AuPdCu/TiO<sub>2</sub> catalysts.</p>
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