Paola Lanzafame

New Sustainable Model of Biorefineries: Biofactories and Challenges of Integrating Bio‐ and Solar Refineries

The new scenario for sustainable (low-carbon) chemical and energy production drives the development of new biorefinery concepts (indicated as biofactories) with chemical production at the core, but flexible and small-scale production. An important element is also the integration of solar energy and CO2 use within biobased production. This concept paper, after shortly introducing the motivation and recent trends in this area, particularly at the industrial scale, and some of the possible models (olefin and intermediate/high-added-value chemicals production), discusses the opportunities and needs for research to address the challenge of integrating bio- and solar refineries. Aspects discussed regard the use of microalgae and CO2 valorization in biorefineries/biofactories by chemo- or biocatalysis, including possibilities for their synergetic cooperation and symbiosis, as well as integration within the agroenergy value chain.

Nanostructured electrocatalytic Pt-carbon materials for fuel cells and CO2 conversion

The recent growing possibilities for the preparation, in large quantities and at low cost, of a number of different types of nanostructured carbons (carbon nanotubes, nanofibers, nano-and meso-porous materials, nanocoils and nanohorns, etc.) have open new possibilities in a range of applications: H2 storage, electronic and field emission devices, advanced sensors, polymer reinforcement, and catalyst support. Nonetheless, most authors consider the use of these advanced nanostructured carbons with respect to carbon black only for the possibility of improving metal dispersion and/or utilization. However, these nanostructured carbons offer several additional aspects that make them highly interesting to develop advanced electrocatalysts.

Disruptive catalysis by zeolites

The analysis of the new scenario for the industrial production of energy vectors and chemicals evidences the need to foster research in the field of catalysis by zeolites towards a novel, potentially disruptive, type of applications. To stimulate research in this direction, this perspective paper analyses a series of emerging concepts in catalysis by zeolites: i) the role of confinement, ii) the use of the Lewis acidity of zeolites, iii) the new possibilities to extend the concept of confined reactivity, iv) the role of defect sites, and iv) the organo-catalysis by guest species in zeolite cages. Then, two areas of novel possibilities for catalysis by zeolites are discussed more specifically: i) metallo-zeolites for methane conversion and ii) functionalized zeolites for reaction with CO2.

HMF etherification using NH4-exchanged zeolites

The properties of BEA, MFI and Silicalite-1 zeolites in the ammonium and protonic forms are studied in the etherification of HMF (5-hydroxymethylfurfural) in anhydrous ethanol and compared with FTIR data on ammonium ion siting and displacement by competitive adsorption, as well as data on ammonium ion dissolution in aqueous solution. For the first time it is demonstrated that ammonium-exchanged zeolites are active and show better performances (particularly for the BEA structure) in the acid-catalyzed etherification reaction. This behavior is associated to a reversible dissociation of NH4+ ions, which is favored by the BEA zeolite structure. A critical condition for enhanced catalytic performances is that dissociated ammonia remains in the zeolite cages, and may be reversibly re-adsorbed. It is thus likely that the dissociated ammonia participates in the reaction or induces a confinement effect.

Grand challenges for catalysis in the Science and Technology Roadmap on Catalysis for Europe: moving ahead for a sustainable future

This perspective discusses the general concepts that will guide future catalysis and related grand challenges based on the Science and Technology Roadmap on Catalysis for Europe prepared by the European Cluster on Catalysis. To address the changing scenarios in refinery and chemical production and move to a low-carbon sustainable future, the distinguishing elements of three grand challenges for catalysis are discussed here: 1) catalysis to address the evolving energy and chemical scenario, 2) catalysis for a cleaner and sustainable future, and 3) addressing catalysis complexity, the latter being organized into three sub-topics: advanced design of novel catalysts, understanding catalysts from the molecular to the material scale, and expanding catalysis concepts.

Introduction and General Overview

Catalysis plays a key role to address the challenge of sustainable energy and alternative methods to produce energy with respect to using fossil fuels. This field of research and development has given a new impetus to research on catalysis in areas such as producing biofuels, development of advanced electrodes for a number of applications (from new-generation photovoltaic cells to fuel cells), production of renewable H2 and in a longer-term perspective solar fuels. However, the discussion on the technical aspects on the development of catalysts in these areas should be complemented with considerations on the general economic and social context and related constrains which determine the choice of the research priorities. This introductory chapter was mainly focused on these aspects.

Nature of corona in TiO2@SBA15-like mesoporous nanocomposite

Abstract TiO 2 @SBA15-like mesoporous nanocomposite, where the symbol @ indicates inclusion, were prepared by introducing Ti by a grafting technique (TiO 2 loadings about 10% wt.) and characterized by different methods. Three different Ti species were evidenced to be present. The first two derive from the reaction of Ti with silanol groups in the corona area of inner SBA15-like walls leading to the formation of either TiO 4 tetrahedral sites and/or pseudo-octahedral surface sites anchored by two (or more) Si or Ti ions through bridging oxygen. The third species derives from the reaction of Ti in the regions with high silanol density, e.g. in the micropores located in the corona of SBA15-like channels, leading to the formation of TiO 2 -like nanoareas with dimensions of around 1-2 nm and having characteristics different from those of crystalline titania as shown by FTIR data.

Monitoring of glucose in fermentation processes by using Au/TiO2 composites as novel modified electrodes

This paper demonstrates an effective method of monitoring glucose in fermentation processes based on the development of enzyme-free glucose electrochemical sensors. The sensing electrodes were manufactured by preparing size-controlled Au nanoparticles (NPs), in the form of colloidal solutions, which were dispersed on TiO2 substrates, and then deposited on commercial carbon screen printed electrodes. The as-synthesized samples were fully characterized by transmission electron microscopy, X-ray diffraction, atomic absorption spectroscopy, and UV–visible diffuse reflectance spectroscopy to obtain information about their morphological, structural, and electronic properties. Particularly, the ability to control the size of Au NPs in the colloidal solution by using different reducing agents and stabilizers is presented here. The Au/TiO2-based modified sensors were assembled and tested for glucose monitoring in an alkaline solution. Results of cyclic voltammetry showed the high electrocatalytic activity of these sensors toward glucose oxidation, whereas no response was detected toward ethanol. This suggests the possibility of using this type of sensor for glucose monitoring in the fermentation processes without ethanol interference. The efficient sensing properties of Au NP-embedded TiO2 composites may be ascribed to the higher electrocatalytic activity of smaller Au NPs stabilized on TiO2.

Analytical assessment to develop innovative nanostructured BPA-free epoxy-silica resins as multifunctional stone conservation materials

Bisphenol A (BPA)-free epoxy resins, synthesized from low molecular weight cycloaliphatic compounds, may represents promising materials for stone conservation due to their very appealing and tunable physico-chemical properties, such as viscosity, curing rate and penetration ability, being also easy to apply and handle. Furthermore, alkoxysilanes have been widely employed as inorganic strengtheners since they are easily hydrolysed inside lithic substrates affording SiO linkages with the stone matrix. Taking into account the advantages of these two classes of materials, this work has been focused on the development of innovative conservation materials, based on hybrid epoxy-silica BPA-free resins obtained by reaction of 1,4-cycloexanedimethanol diglycidylether (CHDM-DGE) with various siloxane precursors, i.e. glycidoxypropylmethyldiethoxysilane (GPTMS), tetraethyl orthosilicate (TEOS) and isobutyltrimethoxysilane (iBuTMS), using the 1,8-diaminooctane (DAO) as epoxy hardener. Thanks to Raman spectroscopy the synthesis processes have been successfully monitored, allowing the identification of oxirane rings opening as well as the formation of the cross-linked organic-inorganic networks. In accordance with the spectroscopic data, the thermal studies carried out by TGA and DSC techniques have pointed that GPTMS is a suitable siloxane precursor to synthesize the most stable samples against temperature degradation. GPTMS-containing resins have also shown good performances in the dynamic mechanical analysis (DMA) and in contact angle investigations, with values indicating considerable hydrophobic properties. SEM analyses have highlighted a great homogeneity over the entire observed areas, without formations of clusters and/or aggregates bigger than 45 μm, for the cited materials, confirming the efficiency of GPTMS as coupling agent to enhance the organic/inorganic interphase bonding. The variations provided by the incorporation of nanostructured titania, specifically synthesized, inside the epoxy-silica hybrids have been also evaluated. According to all the collected results, the hybrid materials here reported have proven to be promising multifunctional products for potential application in the field of stone conservation.

Direct versus acetalization routes in the reaction network of catalytic HMF etherification

The etherification of HMF (5-hydroxymethylfurfural) to EMF (5-(ethoxymethyl)furan-2-carbaldehyde) is studied over a series of MFI-type zeolite catalysts containing different heteroatoms (B, Fe, Al), aiming to understand the effect of different isomorph substitutions in the MFI framework on the reaction pathways of HMF conversion. The rate constants in the reaction network are determined for these different catalysts and analyzed with respect to the amount of Bronsted and Lewis acid sites determined by FT-IR pyridine adsorption. Two different pathways of EMF formation, i.e. direct etherification and via acetalization, were evidenced. The Lewis acid sites generated from the presence of aluminum are primarily active in catalyzing direct HMF etherification to EMF, which has a rate constant about one order of magnitude lower than the etherification of the corresponding acetals. This behaviour is due to the competitive chemisorption between hydroxyl and aldehyde groups (both present in HMF) on the Lewis acid sites catalyzing the etherification. A cooperation phenomenon between Bronsted and Lewis acid sites is observed for the HMF acetal etherification to EMF acetal. In the reactions of direct HMF acetalization and deacetalization of the EMF acetal, the turnover frequencies for Silicalite-1 and B-MFI samples are about twice those for Fe-MFI and Al-MFI samples. This is attributed to the different reactivity of strong silanol groups associated with surface defects on the external surface in Silicalite-1 and B-MFI. These sites are also responsible for the EMF-to-EOP (ethyl 4-oxopentanoate) reaction step. In the deacetalization reaction of the EMF acetal, the behavior is determined from the presence of water (product of reaction) favouring the back reaction (aldehyde formation).