Browsing by Author "Andreoli, Enrico"

Now showing 1 - 8 of 8
  • Thumbnail Image
    Item
    CO2 Adsorption by para-Nitroaniline Sulfuric Acid-Derived Porous Carbon Foam
    (MDPI, 2016) Andreoli, Enrico; Barron, Andrew R.
    The expansion product from the sulfuric acid dehydration of para-nitroaniline has been characterized and studied for CO2 adsorption. The X-ray photoelectron spectroscopy (XPS) characterization of the foam indicates that both N and S contents (15 and 9 wt%, respectively) are comparable to those separately reported for nitrogen- or sulfur-containing porous carbon materials. The analysis of the XPS signals of C1s, O1s, N1s, and S2p reveals the presence of a large number of functional groups and chemical species. The CO2 adsorption capacity of the foam is 7.9 wt% (1.79 mmol/g) at 24.5 °C and 1 atm in 30 min, while the integral molar heat of adsorption is 113.6 kJ/mol, indicative of the fact that chemical reactions characteristic of amine sorbents are observed for this type of carbon foam. The kinetics of adsorption is of pseudo-first-order with an extrapolated activation energy of 18.3 kJ/mol comparable to that of amine-modified nanocarbons. The richness in functionalities of H2SO4-expanded foams represents a valuable and further pursuable approach to porous carbons alternative to KOH-derived activated carbons.
  • Thumbnail Image
    Item
    Cross-Linking Amine-Rich Compounds into High Performing Selective CO2 Absorbents
    (Nature Publishing Group, 2014) Andreoli, Enrico; Dillon, Eoghan P.; Cullum, Laurie; Alemany, Lawrence B.; Barron, Andrew R.; Shared Equipment Authority
    Amine-based absorbents play a central role in CO2 sequestration and utilization. Amines react selectively with CO2, but a drawback is the unproductive weight of solvent or support in the absorbent. Efforts have focused on metal organic frameworks (MOFs) reaching extremely high CO2 capacity, but limited selectivity to N2 and CH4, and decreased uptake at higher temperatures. A desirable system would have selectivity (cf. amine) and high capacity (cf. MOF), but also increased adsorption at higher temperatures. Here, we demonstrate a proof-of-concept where polyethyleneimine (PEI) is converted to a high capacity and highly selective CO2 absorbent using buckminsterfullerene (C60) as a cross-linker. PEI-C60 (CO2 absorption of 0.14 g/g at 0.1 bar/90°C) is compared to one of the best MOFs, Mg-MOF-74 (0.06 g/g at 0.1 bar/90°C), and does not absorb any measurable amount of CH4 at 50 bar. Thus, PEI-C60 can perform better than MOFs in the sweetening of natural gas.
  • Thumbnail Image
    Item
    Easily Regenerated Readily Deployable Absorbent for Heavy Metal Removal from Contaminated Water
    (Springer Nature, 2017) Alagappan, Perry N.; Heimann, Jessica; Morrow, Lauren; Andreoli, Enrico; Barron, Andrew R.
    Although clean and abundant water is the keystone of thriving communities, increasing demand and volatile climate patterns are depleting rivers and aquifers. Moreover, the quality of such water sources is threatened by noxious contaminants, of which heavy metals represents an area of growing concern. Recently, graphene oxide (GO) has been suggested as an adsorbent; however, a support is desirable to ensure a high surface area and an immobile phase. Herein, we described the preparation and characterization of a supported-epoxidized carbon nanotube (SENT) via the growth of multi walled carbon nanotubes (MWNTs) onto a quartz substrate. Subsequent epoxidation provides sufficient functionality to enable adsorbent of heavy metals (Cd2+, Co2+, Cu2+, Hg2+, Ni2+, and Pb2+) from aqueous solution with initial concentrations (60–6000 ppm) chosen to simulate high industrial wastewater contamination. The SENT adsorption efficiency is >99.4% for all metals and the saturation concentration is significantly greater than observed for either GO or acid treated MWNTs. The SENT adsorbent may be readily regenerated under mild conditions using a globally available household chemical, vinegar. 1 g of SENT has the potential to treat 83,000 L of contaminated water down to WHO limits which would be sufficient for 11,000 people.
  • Thumbnail Image
    Item
    Investigation into the Re-Arrangement of Copper Foams Pre- and Post-CO2 Electrocatalysis
    (MDPI, 2021) Rudd, Jennifer A.; Hernandez-Aldave, Sandra; Kazimierska, Ewa; Hamdy, Louise B.; Bain, Odin J.E.; Barron, Andrew R.; Andreoli, Enrico
    The utilization of carbon dioxide is a major incentive for the growing field of carbon capture. Carbon dioxide could be an abundant building block to generate higher-value chemical products. Herein, we fabricated a porous copper electrode capable of catalyzing the reduction of carbon dioxide into higher-value products, such as ethylene, ethanol and propanol. We investigated the formation of the foams under different conditions, not only analyzing their morphological and crystal structure, but also documenting their performance as a catalyst. In particular, we studied the response of the foams to CO2 electrolysis, including the effect of urea as a potential additive to enhance CO2 catalysis. Before electrolysis, the pristine and urea-modified foam copper electrodes consisted of a mixture of cuboctahedra and dendrites. After 35 min of electrolysis, the cuboctahedra and dendrites underwent structural rearrangement affecting catalysis performance. We found that alterations in the morphology, crystallinity and surface composition of the catalyst were conducive to the deactivation of the copper foams.
  • Thumbnail Image
    Item
    Overcoming mass transfer limitations in cross-linked polyethyleneimine-based adsorbents to enable selective CO2 capture at ambient temperature
    (Royal Society of Chemistry, 2022) Hamdy, Louise B.; Gougsa, Abel; Chow, Wing Ying; Russell, James E.; García-Díez, Enrique; Kulakova, Viktoriia; Garcia, Susana; Barron, Andrew R.; Taddei, Marco; Andreoli, Enrico
    New self-supported polyamine CO2 adsorbents are prepared by cross-linking branched polyethyleneimine (PEI) with 2,4,6-tris-(4-bromomethyl-3-fluoro-phenyl)-1,3,5-triazine (4BMFPT). Controlling the degree of cross-linking to ensure abundant free amine functionalities while maintaining a structure conducive to efficient mass transfer is key to accessing high CO2 adsorption and fast kinetics at ambient temperature. The polyamine-based adsorbent, PEI-4BMFPT, 10 : 1 (R), is composed of spherical particles up to 3 μm in diameter and demonstrates fast CO2 uptake of 2.31 mmol g−1 under 1 atm, 90% CO2/Ar at 30 °C. Its CO2/N2 selectivity, predicted by the ideal adsorbed solution theory is 575, equalling that of highly selective metal–organic frameworks. Based on humidified thermogravimetric analysis, it was observed that the presence of water promotes CO2 uptake capacity of 10 : 1 (R) to 3.27 mmol g−1 and results in strong chemisorption; likely by formation of ammonium carbonate and bicarbonate species. It is observed that CO2 uptake enhancement is highly subject to relative humidity and CO2 partial pressure conditions. When adsorption conditions combined low temperatures with low partial pressure CO2, 10 : 1 (R) showed reduced uptake. Tested under breakthrough conditions representative of post-combustion conditions, at 75% RH and 40 °C, CO2 uptake was reduced by 83% of the dry adsorption capacity. This body of work further advances the development of support-free CO2 adsorbents for ambient temperature applications and highlights the drastic effect that relative humidity and CO2 partial pressure have on uptake behaviour.
  • Thumbnail Image
    Item
    Surface-initiated growth of copper using isonicotinic acid-functionalized aluminum oxide surfaces
    (Springer, 2016) Gowenlock, Cathren E.; Gomez, Virginia; McGettrick, James D.; Andreoli, Enrico; Barron, Andrew R.
    Isonicotinate self-assembled monolayers (SAM) were prepared on alumina surfaces (A) using isonicotinic acid (iNA). These functionalized layers (iNA-A) were used for the seeded growth of copper films (Cu-iNA-A) by hydrazine hydrate-initiated electroless deposition. The films were characterized by scanning electron microscopy (SEM), electron-dispersive X-ray spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and advancing contact angle measurements. The films are Cu0 but with surface oxidation, and show a faceted morphology, which is more textured (Rq = 460 ± 90 nm) compared to the SAM (Rq = 2.8 ± 0.5 nm). In contrast, growth of copper films by SnCl2/PdCl2 catalyzed electroless deposition, using formaldehyde (CH2O) as the reducing agent, shows a nodular morphology on top of a relatively smooth surface. No copper films are observed in the absence of the isonicotinate SAM. The binding of Cu2+ to the iNA is proposed to facilitate reduction to Cu0 and create the seed for subsequent growth. The films show good adhesion to the functionalized surface.
  • Thumbnail Image
    Item
    The application of amine-based materials for carbon capture and utilisation: an overarching view
    (Royal Society of Chemistry, 2021) Hamdy, Louise B.; Goel, Chitrakshi; Rudd, Jennifer A.; Barron, Andrew R.; Andreoli, Enrico
    In the ongoing research campaign to reduce the global atmospheric CO2 concentration, technologies are being developed to enable the capture of CO2 from dilute sources and conversion into higher-value products. Amine and polyamine-based materials feature widely in the literature as solid CO2 sorbents and as catalyst modifiers for CO2 electrochemical reduction; however, advancing lab-scale research into a pilot or industrial-scale application is fraught with challenges, starting with the definition and identification of an effective adsorbent. This multidisciplinary review serves as an essential introduction to the role of amines in carbon capture and utilisation for scientists entering and advancing the field. The chemical and engineering principles of amine-based CO2 capture are considered to define the parameters required of an adsorbent, describe adsorption testing methods, and introduce the reader to a range of amine-based adsorbents and how they can be specialised to overcome specific issues. Finally, the application of electrocatalysts modified with nitrogen-containing compounds and polymers is reviewed in the context of CO2 utilisation.
  • Thumbnail Image
    Item
    Understanding the effect of carbon nanotube functionalization on copper electrodeposition
    (Springer, 2019) Kazimierska, Ewa; Andreoli, Enrico; Barron, Andrew R.
    The dynamics of electrochemical deposition and dissolution of copper in the presence of functionalized multiwalled carbon nanotubes in solution has been studied in detail using an electrochemical quartz crystal microbalance. Results demonstrate the central role of carbon nanotube functionalization on the values of mass and current densities of copper deposition. Amine functionalization increases competitive hydrogen evolution without significantly affecting the total amount of deposited copper, whereas carboxylic functionalization clearly enhances the deposition of larger amounts of smoother copper deposits. Molar mass analysis of deposited species reveals interactions of carbon nanotubes with the electrode surface dependent on the type of functionalization. The effect of carbon nanotube functionalization should be closely considered in the development of electrochemical strategies for the integration of carbon nanotubes in metallic copper.