Paolo Pescarmona | University of Groningen (original) (raw)

Papers by Paolo Pescarmona

Research paper thumbnail of Nanostructured anode materials for high-energy Li-/Na-ion large-scale energy storage

Due to their high volumetric and gravimetric capacities, Li-ion batteries (LiBs) are currently co... more Due to their high volumetric and gravimetric capacities, Li-ion batteries (LiBs) are currently considered as the only viable energy storage solution for portable electronics and hybrid vehicles. Nevertheless, concerns on the availability of Li resources and their uneven distribution across the world are growing. As an alternative, Na-ion batteries (NiBs) are highly attractive due to the abundance of Na as well as its electrochemical similarity with Li. Na is also environmentally benign, thus promising a more sustainable energy storage. Although NiBs are unlikely to outperform LiBs in energy density, they are being actively pursued for low-cost grid storage where size or weight is not the most critical factor. The identification of a high-performance anode is a key challenge, particularly for NiBs. Anode materials investigated so far for NiBs can be classified into three categories: (i) layered materials, such as titania or titanates and transition metal dichalcogenides with a specif...

Research paper thumbnail of Unravelling and overcoming the challenges of the electrocatalytic reduction of fructose to sorbitol

Green Chemistry

In this work, we present a comprehensive study on the electrocatalytic reduction of fructose to s... more In this work, we present a comprehensive study on the electrocatalytic reduction of fructose to sorbitol and mannitol, in mild alkaline medium (pH = 11.3), and by using a Cu-wire...

Research paper thumbnail of Binderless zeolite LTA beads with hierarchical porosity for selective CO2 adsorption in biogas upgrading

Microporous and Mesoporous Materials

Research paper thumbnail of <tex>Pr/ZrO_{2}$</tex> prepared by atomic trapping : an efficient catalyst for the conversion of glycerol to lactic acid with concomitant transfer hydrogenation of cyclohexene

A series of heterogeneous catalysts consisting of highly dispersed Pt nanoparticles supported on ... more A series of heterogeneous catalysts consisting of highly dispersed Pt nanoparticles supported on nanosized ZrO 2 (20 to 60 nm) was synthesized and investigated for the one-pot transfer hydrogenation between glycerol and cyclohexene to produce lactic acid and cyclohexane, without any additional H 2. Different preparation methods were screened, by varying the calcination and reduction procedures with the purpose of optimizing the dispersion of Pt species (i.e., as single-atom sites or extra-fine Pt nanoparticles) on the ZrO 2 support. The Pt/ZrO 2 catalysts were characterized by means of transmission electron microscopy techniques (HAADF-STEM, TEM), elemental analysis (ICP-OES, EDX mapping), N 2physisorption, H 2 temperature-programmed-reduction (H 2-TPR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Based on this combination of techniques it was possible to correlate the temperature of the calcination and reduction treatments with the nature of the Pt species. The best catalyst consisted of subnanometer Pt clusters (<1 nm) and atomically dispersed Pt (as Pt 2+ and Pt 4+) on the ZrO 2 support, which were converted into extra-fine Pt nanoparticles (average size = 1.4 nm) upon reduction. These nanoparticles acted as catalytic species for the transfer hydrogenation of glycerol with cyclohexene, which gave an unsurpassed 95% yield of lactic acid salt at 96% glycerol conversion (aqueous glycerol solution, NaOH as promoter, 160°C, 4.5 h, at 20 bar N 2). This is the highest yield and selectivity of lactic acid (salt) reported in the literature so far. Reusability experiments showed a partial and gradual loss of activity of the Pt/ZrO 2 catalyst, which was attributed to the experimentally observed aggregation of Pt nanoparticles.

Research paper thumbnail of Binder‐free Zeolite Beta Beads with Hierarchical Porosity: Synthesis and Application as Heterogeneous Catalysts for Anisole Acylation

Research paper thumbnail of An Agent-Based Model of COVID-19 Diffusion to Plan and Evaluate Intervention Policies

Crowd Dynamics, Volume 3, 2021

A model of interacting agents, following plausible behavioral rules into a world where the Covid-... more A model of interacting agents, following plausible behavioral rules into a world where the Covid-19 epidemic is affecting the actions of everyone. The model works with (i) infected agents categorized as symptomatic or asymptomatic and (ii) the places of contagion specified in a detailed way. The infection transmission is related to three factors: the characteristics of both the infected person and the susceptible one, plus those of the space in which contact occurs. The model includes the structural data of Piedmont, an Italian region, but we can easily calibrate it for other areas. The micro-based structure of the model allows factual, counterfactual, and conditional simulations to investigate both the spontaneous or controlled development of the epidemic. The model is generative of complex epidemic dynamics emerging from the consequences of agents' actions and interactions, with high variability in outcomes and stunning realistic reproduction of the successive contagion waves in the reference region. There is also an inverse generative side of the model, coming from the idea of using genetic algorithms to construct a meta-agent to optimize the vaccine distribution. This agent takes into account groups' characteristics-by age, fragility, work conditions-to minimize the number of symptomatic people.

Research paper thumbnail of Does the use of cash in daily purchases promote the spread of COVID-19?

Hereby, I would like to propose to investigate an aspect of the spread of the COVID-19 virus thro... more Hereby, I would like to propose to investigate an aspect of the spread of the COVID-19 virus through surfaces that, to the best of my knowledge, has not been considered in detail: the use of cash in daily transactions. The question is: would the use of contactless transactions help in limiting the spread of the COVID-19 virus?

Research paper thumbnail of Host(beta zeolite)-guest (copper(n)-methyladenine complex) nanomaterials : synthesis and characterization

New Journal of Chemistry, 2008

Research paper thumbnail of Fast and Selective Sugar Conversion to Alkyl Lactate and Lactic Acid with Bifunctional Carbon–Silica Catalysts

Journal of the American Chemical Society, 2012

A novel catalyst design for the conversion of mono- and disaccharides to lactic acid and its alky... more A novel catalyst design for the conversion of mono- and disaccharides to lactic acid and its alkyl esters was developed. The design uses a mesoporous silica, here represented by MCM-41, which is filled with a polyaromatic to graphite-like carbon network. The particular structure of the carbon-silica composite allows the accommodation of a broad variety of catalytically active functions, useful to attain cascade reactions, in a readily tunable pore texture. The significance of a joint action of Lewis and weak Brønsted acid sites was studied here to realize fast and selective sugar conversion. Lewis acidity is provided by grafting the silica component with Sn(IV), while weak Brønsted acidity originates from oxygen-containing functional groups in the carbon part. The weak Brønsted acid content was varied by changing the amount of carbon loading, the pyrolysis temperature, and the post-treatment procedure. As both catalytic functions can be tuned independently, their individual role and optimal balance can be searched for. It was thus demonstrated for the first time that the presence of weak Brønsted acid sites is crucial in accelerating the rate-determining (dehydration) reaction, that is, the first step in the reaction network from triose to lactate. Composite catalysts with well-balanced Lewis/Brønsted acidity are able to convert the trioses, glyceraldehyde and dihydroxyacetone, quantitatively into ethyl lactate in ethanol with an order of magnitude higher reaction rate when compared to the Sn grafted MCM-41 reference catalyst. Interestingly, the ability to tailor the pore architecture further allows the synthesis of a variety of amphiphilic alkyl lactates from trioses and long chain alcohols in moderate to high yields. Finally, direct lactate formation from hexoses, glucose and fructose, and disaccharides composed thereof, sucrose, was also attempted. For instance, conversion of sucrose with the bifunctional composite catalyst yields 45% methyl lactate in methanol at slightly elevated reaction temperature. The hybrid catalyst proved to be recyclable in various successive runs when used in alcohol solvent.

Research paper thumbnail of University of Groningen Carbon-supported iron complexes as electrocatalysts for the cogeneration of hydroxylamine and electricity in a NO-H-2 fuel cell Sheng

Carbon-supported iron complexes were investigated as electrocatalysts for the reduction of nitric... more Carbon-supported iron complexes were investigated as electrocatalysts for the reduction of nitric oxide (NO) in a H2-NO fuel cell conceived for the production of hydroxylamine (NH2OH) with concomitant generation of electricity. Two types of iron complexes with tetradentate ligands, namely

Research paper thumbnail of WO3–SiO2 nanomaterials synthesized using a novel template-free method in supercritical CO2 as heterogeneous catalysts for epoxidation with H2O2

Materials Today Chemistry

Research paper thumbnail of doped ordered mesoporous carbons prepared by a two-step anocasting strategy as highly active and selective lectrocatalysts for the reduction of O 2 to H 2 O 2

A new, two-step nanocasting method was developed to prepare N-doped ordered mesoporous carbon (NO... more A new, two-step nanocasting method was developed to prepare N-doped ordered mesoporous carbon (NOMC) electrocatalysts for the reduction of O2 to H2O2. Our strategy involves the sequential pyrolysis of two inexpensive and readily available N and C precursors, i.e. aniline and dihydroxynaphthalene (DHN), inside the pores of a SBA-15 hard silica template to obtain N-doped graphitic carbon materials with wellordered pores and high surface areas (764 and 877 m2g−1). By tuning the ratio of carbon sources to silica template, it was possible to achieve an optimal filling of the pores of the SBA-15 silica and to minimise -doped ordered mesoporous carbon

Research paper thumbnail of Bimetallic Zeolite Beta Beads with Hierarchical Porosity as Brønsted-Lewis Solid Acid Catalysts for the Synthesis of Methyl Lactate

Catalysts

Bimetallic zeolite Beta in bead format and containing Al sites with Brønsted acid behavior and Sn... more Bimetallic zeolite Beta in bead format and containing Al sites with Brønsted acid behavior and Sn, Zr or Hf sites with Lewis acid character, were prepared using a two-step synthetic route. First, zeolite Beta in the format of macroscopic beads (400 to 840 μm) with hierarchical porosity (micropores accessed through meso- and macropores in the range of 30 to 150 nm) were synthesized by hydrothermal crystallization in the presence of anion-exchange resin beads as hard template and further converted into their H-form. Next, the zeolite beads were partially dealuminated using different concentrations of HNO3 (i.e., 1.8 or 7.2 M), followed by grafting with one of the above-mentioned metals (Sn, Zr or Hf) to introduce Lewis acid sites. These bimetallic zeolites were tested as heterogeneous catalysts in the conversion of dihydroxyacetone (DHA) to methyl lactate (ML). The Sn-containing zeolite Beta beads treated by 1.8 M HNO3 and grafted with 27 mmol of SnCl4 (Sn-deAl-1.8-Beta-B) demonstrate...

Research paper thumbnail of Novel non-ionic surfactants synthesised through the reaction of CO2 with long alkyl chain epoxides

Journal of CO2 Utilization

Research paper thumbnail of One‐pot Fixation of CO 2 into Glycerol Carbonate using Ion‐Exchanged Amberlite Resin Beads as Efficient Metal‐free Heterogeneous Catalysts

ChemCatChem

Take-down policy If you believe that this document breaches copyright please contact us providing... more Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Research paper thumbnail of An efficient method to prepare supported bismuth nanoparticles as highly selective electrocatalyst for the conversion of CO2 into formate

Chemical Communications

We report a novel and upscalable method to synthesise small, highly dispersed Bi nanoparticles on... more We report a novel and upscalable method to synthesise small, highly dispersed Bi nanoparticles on activated carbon. This electrocatalyst displays outstanding selectivity (FE > 99% at −1.07 V vs. RHE) and stability in the conversion of CO2 to formate.

Research paper thumbnail of Encapsulation of Lactobacillus casei (ATCC 393) by Pickering-Stabilized Antibubbles as a New Method to Protect Bacteria against Low pH

Colloids and Interfaces

Pickering-stabilized antibubbles were used as a new method to encapsulate Lactobacillus casei. An... more Pickering-stabilized antibubbles were used as a new method to encapsulate Lactobacillus casei. Antibubbles consist of one or more liquid droplets within a shell of gas. The antibubbles were prepared from a water-in-oil-in-water (W/O/W) emulsion stabilized by silica particles, which was then freeze-dried to remove the water and oil phases, before being subsequently reconstituted in water. Different oil phases and aqueous phase compositions were tested for their effect on the survival of the bacteria. The survival of L. casei after encapsulation using decane was 29.8 ± 2.1% in antibubbles containing 10% (w/v) maltodextrin plus 8% (w/v) sucrose, which is comparable to the survival when bacteria were freeze-dried without being encapsulated. Encapsulation within antibubbles led to a 10 to 30 times higher survival of L. casei at pH 2 in comparison with unencapsulated bacteria. This study shows that probiotics can be encapsulated within a shell of gas through the use of antibubbles and tha...

Research paper thumbnail of Efficient and Easily Reusable Metal-Free Heterogeneous Catalyst Beads for the Conversion of CO2 into Cyclic Carbonates in the Presence of Water as Hydrogen-Bond Donor

Two porous Amberlite resin beads consisting of ammonium-functionalized polystyrene cross-linked w... more Two porous Amberlite resin beads consisting of ammonium-functionalized polystyrene cross-linked with divinylbenzene were demonstrated to be efficient, easily recyclable, and viable metalfree heterogeneous catalysts for the reaction of CO 2 with epoxides to yield cyclic carbonates. The catalysts were prepared from two affordable, commercially available resin beads, which differ in the nature of their functional groups, i.e., trimethylammonium chloride or dimethylethanolammonium chloride. These materials were converted through a straightforward ion-exchange step into their iodide counterparts (Amb-I-900 and Amb-OH-I-910). The ion-exchanged resin beads were tested as heterogeneous catalysts for the reaction of CO 2 with styrene oxide at different reaction conditions (45−150°C, 2−60 bar of CO 2 , 3−18 h). The effect of the presence of water as a hydrogen-bond donor in combination with a heterogeneous catalyst was systematically investigated here for the first time. With both catalysts, the presence of water led to higher yields of cyclic carbonate (from 12% to 58% with Amb-I-900 and from 59% to 66% with Amb-OH-I-910; ≥98% selectivity). The highest catalytic activity was observed with Amb-OH-I-910, due to the presence of −OH groups in its active site, which together with water enhanced the activity through hydrogen-bonding interactions. This catalytic system attained higher turnover numbers and turnover frequencies (TON = 505, TOF = 168 for reaction at 150°C) and improved cyclic carbonate productivity compared to the state-of-the-art supported polymeric bead catalysts and was active in catalyzing the synthesis of styrene carbonate also at low temperature (33% yield at 45°C and 10 bar of CO 2). Additionally, the Amb-OH-I-910 proved to be a versatile catalyst for the conversion of a variety of epoxides into their corresponding cyclic carbonates with good to excellent yields and very high selectivity (≥98%). The two polymeric bead catalysts could be easily recovered and reused without significant loss in their activity and thus represent an easily accessible, environmentally friendly, cost-effective catalytic system for the synthesis of cyclic carbonates from CO 2 .

Research paper thumbnail of Transfer hydrogenation from glycerol over a Ni-Co/CeO2 catalyst: a highly efficient and sustainable route to produce lactic acid

Applied Catalysis B: Environmental

Bimetallic Ni-Co catalysts supported on nanosized CeO 2 were prepared and investigated as heterog... more Bimetallic Ni-Co catalysts supported on nanosized CeO 2 were prepared and investigated as heterogeneous catalysts for the transfer hydrogenation between glycerol and various H 2 acceptors (levulinic acid, benzene, nitrobenzene, 1-decene, cyclohexene) to selectively produce lactic acid (salt) and the target hydrogenated compound. The bimetallic NiCo/CeO 2 catalyst showed much higher activity than the monometallic Ni or Co counterparts (with equal total metal mass), thus indicating strong synergetic effects. The interaction between the metallic sites and the CeO 2 support was thoroughly characterised by means of transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDX) mapping, X-ray photoelectron spectroscopy (XPS), hydrogen-temperature programmed reduction (H 2-TPR) and Xray diffraction (XRD). Combining characterisation and catalytic results proved that the Ni species are intrinsically more active than Co species, but that incorporating Co into the catalyst formulation prevented the formation of large Ni particles and led to highly dispersed metal nanoparticles on CeO 2 , thus leading to the observed enhanced activity for the bimetallic system. The highest yield of lactic acid (salt) achieved in this work was 93% at 97% glycerol conversion (160°C, 6.5 h at 20 bar N 2 , NaOH: glycerol = 1.5). The NiCo/CeO 2 catalyst also exhibited high activity and selectivity towards the target hydrogenated products in the transfer hydrogenation reactions between glycerol and various H 2 acceptors. Batch recycle experiments showed good reusability, with retention of 80% of the original activity after 5 runs.

Research paper thumbnail of Nanostructured Oxides Synthesised via scCO2-Assisted Sol-Gel Methods and Their Application in Catalysis

Catalysts

Nanostructured metal oxides and silicates are increasingly applied in catalysis, either as suppor... more Nanostructured metal oxides and silicates are increasingly applied in catalysis, either as supports or as active species in heterogeneous catalysts, owing to the physicochemical properties that typically distinguish them from bulk oxides, such as higher surface area and a larger fraction of coordinatively unsaturated sites at their surface. Among the different synthetic routes for preparing these oxides, sol-gel is a relatively facile and efficient method. The use of supercritical CO 2 (scCO 2) in the sol-gel process can be functional to the formation of nanostructured materials. The physical properties of the scCO 2 medium can be controlled by adjusting the processing temperature and the pressure of CO 2 , thus enabling the synthesis conditions to be tuned. This paper provides a review of the studies on the synthesis of oxide nanomaterials via scCO 2-assisted sol-gel methods and their catalytic applications. The advantages brought about by scCO 2 in the synthesis of oxides are described, and the performance of oxide-based catalysts prepared by scCO 2 routes is compared to their counterparts prepared via non-scCO 2-assisted methods.

Research paper thumbnail of Nanostructured anode materials for high-energy Li-/Na-ion large-scale energy storage

Due to their high volumetric and gravimetric capacities, Li-ion batteries (LiBs) are currently co... more Due to their high volumetric and gravimetric capacities, Li-ion batteries (LiBs) are currently considered as the only viable energy storage solution for portable electronics and hybrid vehicles. Nevertheless, concerns on the availability of Li resources and their uneven distribution across the world are growing. As an alternative, Na-ion batteries (NiBs) are highly attractive due to the abundance of Na as well as its electrochemical similarity with Li. Na is also environmentally benign, thus promising a more sustainable energy storage. Although NiBs are unlikely to outperform LiBs in energy density, they are being actively pursued for low-cost grid storage where size or weight is not the most critical factor. The identification of a high-performance anode is a key challenge, particularly for NiBs. Anode materials investigated so far for NiBs can be classified into three categories: (i) layered materials, such as titania or titanates and transition metal dichalcogenides with a specif...

Research paper thumbnail of Unravelling and overcoming the challenges of the electrocatalytic reduction of fructose to sorbitol

Green Chemistry

In this work, we present a comprehensive study on the electrocatalytic reduction of fructose to s... more In this work, we present a comprehensive study on the electrocatalytic reduction of fructose to sorbitol and mannitol, in mild alkaline medium (pH = 11.3), and by using a Cu-wire...

Research paper thumbnail of Binderless zeolite LTA beads with hierarchical porosity for selective CO2 adsorption in biogas upgrading

Microporous and Mesoporous Materials

Research paper thumbnail of <tex>Pr/ZrO_{2}$</tex> prepared by atomic trapping : an efficient catalyst for the conversion of glycerol to lactic acid with concomitant transfer hydrogenation of cyclohexene

A series of heterogeneous catalysts consisting of highly dispersed Pt nanoparticles supported on ... more A series of heterogeneous catalysts consisting of highly dispersed Pt nanoparticles supported on nanosized ZrO 2 (20 to 60 nm) was synthesized and investigated for the one-pot transfer hydrogenation between glycerol and cyclohexene to produce lactic acid and cyclohexane, without any additional H 2. Different preparation methods were screened, by varying the calcination and reduction procedures with the purpose of optimizing the dispersion of Pt species (i.e., as single-atom sites or extra-fine Pt nanoparticles) on the ZrO 2 support. The Pt/ZrO 2 catalysts were characterized by means of transmission electron microscopy techniques (HAADF-STEM, TEM), elemental analysis (ICP-OES, EDX mapping), N 2physisorption, H 2 temperature-programmed-reduction (H 2-TPR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Based on this combination of techniques it was possible to correlate the temperature of the calcination and reduction treatments with the nature of the Pt species. The best catalyst consisted of subnanometer Pt clusters (<1 nm) and atomically dispersed Pt (as Pt 2+ and Pt 4+) on the ZrO 2 support, which were converted into extra-fine Pt nanoparticles (average size = 1.4 nm) upon reduction. These nanoparticles acted as catalytic species for the transfer hydrogenation of glycerol with cyclohexene, which gave an unsurpassed 95% yield of lactic acid salt at 96% glycerol conversion (aqueous glycerol solution, NaOH as promoter, 160°C, 4.5 h, at 20 bar N 2). This is the highest yield and selectivity of lactic acid (salt) reported in the literature so far. Reusability experiments showed a partial and gradual loss of activity of the Pt/ZrO 2 catalyst, which was attributed to the experimentally observed aggregation of Pt nanoparticles.

Research paper thumbnail of Binder‐free Zeolite Beta Beads with Hierarchical Porosity: Synthesis and Application as Heterogeneous Catalysts for Anisole Acylation

Research paper thumbnail of An Agent-Based Model of COVID-19 Diffusion to Plan and Evaluate Intervention Policies

Crowd Dynamics, Volume 3, 2021

A model of interacting agents, following plausible behavioral rules into a world where the Covid-... more A model of interacting agents, following plausible behavioral rules into a world where the Covid-19 epidemic is affecting the actions of everyone. The model works with (i) infected agents categorized as symptomatic or asymptomatic and (ii) the places of contagion specified in a detailed way. The infection transmission is related to three factors: the characteristics of both the infected person and the susceptible one, plus those of the space in which contact occurs. The model includes the structural data of Piedmont, an Italian region, but we can easily calibrate it for other areas. The micro-based structure of the model allows factual, counterfactual, and conditional simulations to investigate both the spontaneous or controlled development of the epidemic. The model is generative of complex epidemic dynamics emerging from the consequences of agents' actions and interactions, with high variability in outcomes and stunning realistic reproduction of the successive contagion waves in the reference region. There is also an inverse generative side of the model, coming from the idea of using genetic algorithms to construct a meta-agent to optimize the vaccine distribution. This agent takes into account groups' characteristics-by age, fragility, work conditions-to minimize the number of symptomatic people.

Research paper thumbnail of Does the use of cash in daily purchases promote the spread of COVID-19?

Hereby, I would like to propose to investigate an aspect of the spread of the COVID-19 virus thro... more Hereby, I would like to propose to investigate an aspect of the spread of the COVID-19 virus through surfaces that, to the best of my knowledge, has not been considered in detail: the use of cash in daily transactions. The question is: would the use of contactless transactions help in limiting the spread of the COVID-19 virus?

Research paper thumbnail of Host(beta zeolite)-guest (copper(n)-methyladenine complex) nanomaterials : synthesis and characterization

New Journal of Chemistry, 2008

Research paper thumbnail of Fast and Selective Sugar Conversion to Alkyl Lactate and Lactic Acid with Bifunctional Carbon–Silica Catalysts

Journal of the American Chemical Society, 2012

A novel catalyst design for the conversion of mono- and disaccharides to lactic acid and its alky... more A novel catalyst design for the conversion of mono- and disaccharides to lactic acid and its alkyl esters was developed. The design uses a mesoporous silica, here represented by MCM-41, which is filled with a polyaromatic to graphite-like carbon network. The particular structure of the carbon-silica composite allows the accommodation of a broad variety of catalytically active functions, useful to attain cascade reactions, in a readily tunable pore texture. The significance of a joint action of Lewis and weak Brønsted acid sites was studied here to realize fast and selective sugar conversion. Lewis acidity is provided by grafting the silica component with Sn(IV), while weak Brønsted acidity originates from oxygen-containing functional groups in the carbon part. The weak Brønsted acid content was varied by changing the amount of carbon loading, the pyrolysis temperature, and the post-treatment procedure. As both catalytic functions can be tuned independently, their individual role and optimal balance can be searched for. It was thus demonstrated for the first time that the presence of weak Brønsted acid sites is crucial in accelerating the rate-determining (dehydration) reaction, that is, the first step in the reaction network from triose to lactate. Composite catalysts with well-balanced Lewis/Brønsted acidity are able to convert the trioses, glyceraldehyde and dihydroxyacetone, quantitatively into ethyl lactate in ethanol with an order of magnitude higher reaction rate when compared to the Sn grafted MCM-41 reference catalyst. Interestingly, the ability to tailor the pore architecture further allows the synthesis of a variety of amphiphilic alkyl lactates from trioses and long chain alcohols in moderate to high yields. Finally, direct lactate formation from hexoses, glucose and fructose, and disaccharides composed thereof, sucrose, was also attempted. For instance, conversion of sucrose with the bifunctional composite catalyst yields 45% methyl lactate in methanol at slightly elevated reaction temperature. The hybrid catalyst proved to be recyclable in various successive runs when used in alcohol solvent.

Research paper thumbnail of University of Groningen Carbon-supported iron complexes as electrocatalysts for the cogeneration of hydroxylamine and electricity in a NO-H-2 fuel cell Sheng

Carbon-supported iron complexes were investigated as electrocatalysts for the reduction of nitric... more Carbon-supported iron complexes were investigated as electrocatalysts for the reduction of nitric oxide (NO) in a H2-NO fuel cell conceived for the production of hydroxylamine (NH2OH) with concomitant generation of electricity. Two types of iron complexes with tetradentate ligands, namely

Research paper thumbnail of WO3–SiO2 nanomaterials synthesized using a novel template-free method in supercritical CO2 as heterogeneous catalysts for epoxidation with H2O2

Materials Today Chemistry

Research paper thumbnail of doped ordered mesoporous carbons prepared by a two-step anocasting strategy as highly active and selective lectrocatalysts for the reduction of O 2 to H 2 O 2

A new, two-step nanocasting method was developed to prepare N-doped ordered mesoporous carbon (NO... more A new, two-step nanocasting method was developed to prepare N-doped ordered mesoporous carbon (NOMC) electrocatalysts for the reduction of O2 to H2O2. Our strategy involves the sequential pyrolysis of two inexpensive and readily available N and C precursors, i.e. aniline and dihydroxynaphthalene (DHN), inside the pores of a SBA-15 hard silica template to obtain N-doped graphitic carbon materials with wellordered pores and high surface areas (764 and 877 m2g−1). By tuning the ratio of carbon sources to silica template, it was possible to achieve an optimal filling of the pores of the SBA-15 silica and to minimise -doped ordered mesoporous carbon

Research paper thumbnail of Bimetallic Zeolite Beta Beads with Hierarchical Porosity as Brønsted-Lewis Solid Acid Catalysts for the Synthesis of Methyl Lactate

Catalysts

Bimetallic zeolite Beta in bead format and containing Al sites with Brønsted acid behavior and Sn... more Bimetallic zeolite Beta in bead format and containing Al sites with Brønsted acid behavior and Sn, Zr or Hf sites with Lewis acid character, were prepared using a two-step synthetic route. First, zeolite Beta in the format of macroscopic beads (400 to 840 μm) with hierarchical porosity (micropores accessed through meso- and macropores in the range of 30 to 150 nm) were synthesized by hydrothermal crystallization in the presence of anion-exchange resin beads as hard template and further converted into their H-form. Next, the zeolite beads were partially dealuminated using different concentrations of HNO3 (i.e., 1.8 or 7.2 M), followed by grafting with one of the above-mentioned metals (Sn, Zr or Hf) to introduce Lewis acid sites. These bimetallic zeolites were tested as heterogeneous catalysts in the conversion of dihydroxyacetone (DHA) to methyl lactate (ML). The Sn-containing zeolite Beta beads treated by 1.8 M HNO3 and grafted with 27 mmol of SnCl4 (Sn-deAl-1.8-Beta-B) demonstrate...

Research paper thumbnail of Novel non-ionic surfactants synthesised through the reaction of CO2 with long alkyl chain epoxides

Journal of CO2 Utilization

Research paper thumbnail of One‐pot Fixation of CO 2 into Glycerol Carbonate using Ion‐Exchanged Amberlite Resin Beads as Efficient Metal‐free Heterogeneous Catalysts

ChemCatChem

Take-down policy If you believe that this document breaches copyright please contact us providing... more Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Research paper thumbnail of An efficient method to prepare supported bismuth nanoparticles as highly selective electrocatalyst for the conversion of CO2 into formate

Chemical Communications

We report a novel and upscalable method to synthesise small, highly dispersed Bi nanoparticles on... more We report a novel and upscalable method to synthesise small, highly dispersed Bi nanoparticles on activated carbon. This electrocatalyst displays outstanding selectivity (FE > 99% at −1.07 V vs. RHE) and stability in the conversion of CO2 to formate.

Research paper thumbnail of Encapsulation of Lactobacillus casei (ATCC 393) by Pickering-Stabilized Antibubbles as a New Method to Protect Bacteria against Low pH

Colloids and Interfaces

Pickering-stabilized antibubbles were used as a new method to encapsulate Lactobacillus casei. An... more Pickering-stabilized antibubbles were used as a new method to encapsulate Lactobacillus casei. Antibubbles consist of one or more liquid droplets within a shell of gas. The antibubbles were prepared from a water-in-oil-in-water (W/O/W) emulsion stabilized by silica particles, which was then freeze-dried to remove the water and oil phases, before being subsequently reconstituted in water. Different oil phases and aqueous phase compositions were tested for their effect on the survival of the bacteria. The survival of L. casei after encapsulation using decane was 29.8 ± 2.1% in antibubbles containing 10% (w/v) maltodextrin plus 8% (w/v) sucrose, which is comparable to the survival when bacteria were freeze-dried without being encapsulated. Encapsulation within antibubbles led to a 10 to 30 times higher survival of L. casei at pH 2 in comparison with unencapsulated bacteria. This study shows that probiotics can be encapsulated within a shell of gas through the use of antibubbles and tha...

Research paper thumbnail of Efficient and Easily Reusable Metal-Free Heterogeneous Catalyst Beads for the Conversion of CO2 into Cyclic Carbonates in the Presence of Water as Hydrogen-Bond Donor

Two porous Amberlite resin beads consisting of ammonium-functionalized polystyrene cross-linked w... more Two porous Amberlite resin beads consisting of ammonium-functionalized polystyrene cross-linked with divinylbenzene were demonstrated to be efficient, easily recyclable, and viable metalfree heterogeneous catalysts for the reaction of CO 2 with epoxides to yield cyclic carbonates. The catalysts were prepared from two affordable, commercially available resin beads, which differ in the nature of their functional groups, i.e., trimethylammonium chloride or dimethylethanolammonium chloride. These materials were converted through a straightforward ion-exchange step into their iodide counterparts (Amb-I-900 and Amb-OH-I-910). The ion-exchanged resin beads were tested as heterogeneous catalysts for the reaction of CO 2 with styrene oxide at different reaction conditions (45−150°C, 2−60 bar of CO 2 , 3−18 h). The effect of the presence of water as a hydrogen-bond donor in combination with a heterogeneous catalyst was systematically investigated here for the first time. With both catalysts, the presence of water led to higher yields of cyclic carbonate (from 12% to 58% with Amb-I-900 and from 59% to 66% with Amb-OH-I-910; ≥98% selectivity). The highest catalytic activity was observed with Amb-OH-I-910, due to the presence of −OH groups in its active site, which together with water enhanced the activity through hydrogen-bonding interactions. This catalytic system attained higher turnover numbers and turnover frequencies (TON = 505, TOF = 168 for reaction at 150°C) and improved cyclic carbonate productivity compared to the state-of-the-art supported polymeric bead catalysts and was active in catalyzing the synthesis of styrene carbonate also at low temperature (33% yield at 45°C and 10 bar of CO 2). Additionally, the Amb-OH-I-910 proved to be a versatile catalyst for the conversion of a variety of epoxides into their corresponding cyclic carbonates with good to excellent yields and very high selectivity (≥98%). The two polymeric bead catalysts could be easily recovered and reused without significant loss in their activity and thus represent an easily accessible, environmentally friendly, cost-effective catalytic system for the synthesis of cyclic carbonates from CO 2 .

Research paper thumbnail of Transfer hydrogenation from glycerol over a Ni-Co/CeO2 catalyst: a highly efficient and sustainable route to produce lactic acid

Applied Catalysis B: Environmental

Bimetallic Ni-Co catalysts supported on nanosized CeO 2 were prepared and investigated as heterog... more Bimetallic Ni-Co catalysts supported on nanosized CeO 2 were prepared and investigated as heterogeneous catalysts for the transfer hydrogenation between glycerol and various H 2 acceptors (levulinic acid, benzene, nitrobenzene, 1-decene, cyclohexene) to selectively produce lactic acid (salt) and the target hydrogenated compound. The bimetallic NiCo/CeO 2 catalyst showed much higher activity than the monometallic Ni or Co counterparts (with equal total metal mass), thus indicating strong synergetic effects. The interaction between the metallic sites and the CeO 2 support was thoroughly characterised by means of transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDX) mapping, X-ray photoelectron spectroscopy (XPS), hydrogen-temperature programmed reduction (H 2-TPR) and Xray diffraction (XRD). Combining characterisation and catalytic results proved that the Ni species are intrinsically more active than Co species, but that incorporating Co into the catalyst formulation prevented the formation of large Ni particles and led to highly dispersed metal nanoparticles on CeO 2 , thus leading to the observed enhanced activity for the bimetallic system. The highest yield of lactic acid (salt) achieved in this work was 93% at 97% glycerol conversion (160°C, 6.5 h at 20 bar N 2 , NaOH: glycerol = 1.5). The NiCo/CeO 2 catalyst also exhibited high activity and selectivity towards the target hydrogenated products in the transfer hydrogenation reactions between glycerol and various H 2 acceptors. Batch recycle experiments showed good reusability, with retention of 80% of the original activity after 5 runs.

Research paper thumbnail of Nanostructured Oxides Synthesised via scCO2-Assisted Sol-Gel Methods and Their Application in Catalysis

Catalysts

Nanostructured metal oxides and silicates are increasingly applied in catalysis, either as suppor... more Nanostructured metal oxides and silicates are increasingly applied in catalysis, either as supports or as active species in heterogeneous catalysts, owing to the physicochemical properties that typically distinguish them from bulk oxides, such as higher surface area and a larger fraction of coordinatively unsaturated sites at their surface. Among the different synthetic routes for preparing these oxides, sol-gel is a relatively facile and efficient method. The use of supercritical CO 2 (scCO 2) in the sol-gel process can be functional to the formation of nanostructured materials. The physical properties of the scCO 2 medium can be controlled by adjusting the processing temperature and the pressure of CO 2 , thus enabling the synthesis conditions to be tuned. This paper provides a review of the studies on the synthesis of oxide nanomaterials via scCO 2-assisted sol-gel methods and their catalytic applications. The advantages brought about by scCO 2 in the synthesis of oxides are described, and the performance of oxide-based catalysts prepared by scCO 2 routes is compared to their counterparts prepared via non-scCO 2-assisted methods.