213 research outputs found
5-Hydroxymethylfurfural (HMF) Production from Real Biomasses
The present paper reviews recent advances on the direct synthesis of 5-hydroxymethylfurfural (HMF) from different kinds of raw biomasses. In particular, in the paper HMF production from: (i) edible biomasses; (ii) non-edible lignocellulosic biomasses; (iii) food wastes (FW) have been reviewed. The different processes and catalytic systems have been reviewed and their merits, demerits and requirements for commercialisation outlined
Innovative Synthetic Approaches for Sulphate-Promoted Catalysts for Biomass Valorisation
In the present research, we report on an innovative and quick procedure for the synthesis
of metal oxides: a sol-gel procedure which is followed by two steps that are assisted by microwaves
(MW) heating. First, MW heating promotes gel drying and successively permits the calcination of the
xerogel in a few minutes, using a susceptor that rapidly reaches high temperatures. The procedure
was employed for the synthesis of zirconium dioxide (ZrO2), and MW-assisted calcination enables
the collection of tetragonal ZrO2, as confirmed by different experimental techniques (PXRD, HR-TEM
and Raman spectroscopy). Using this MW-assisted sol-gel procedure, a promoted sulphated zirconia
(SZ) has been obtained. Both the nature and strength of SZ surface acidity have been investigated with
FTIR spectroscopy using CO and 2,6-dimethylpyridine (2,6-DMP) as probe molecules. The obtained
materials were tested as catalysts in acid hydrolysis of glucose to give 5-(hydroxymethyl)furfural
(5-HMF). One of the obtained catalysts exhibited a better selectivity towards 5-HMF with respect
to SZ material prepared by a classical precipitation route, suggesting that this procedure could be
employed to obtain a well-known catalyst with a less energy-consuming procedure. Catalytic results
also suggest that good selectivity to 5-HMF can be achieved in aqueous media in the presence of
weak Lewis and Brønsted sites
Which Are the Main Surface Disinfection Approaches at the Time of SARS-CoV-2?
Among many guidelines issued by the World Health Organization to prevent contagion
from novel coronavirus (SARS-CoV-2), disinfection of animate and inanimate surfaces has
emerged as a key issue. One effective approach to prevent its propagation can be
achieved by disinfecting air, skin, or surfaces. A thorough and rational application of an
Environmental Protection Agent for disinfection of surfaces, as well as a good personal
hygiene, including cleaning hands with appropriate products (e.g., 60–90% alcohol-based
product) should minimize transmission of viral respiratory pathogens such as SARS-CoV-
2. Critical issues, associated with the potential health hazard of chemical disinfectants and
the ineffective duration of most of the treatments, have fostered the introduction of
innovative and alternative disinfection approaches. The present review aims to provide
an outline of methods currently used for inanimate surface disinfection with a look to the
future and a focus on the development of innovative and effective disinfection approaches
(e.g., metal nanoparticles, photocatalysis, self-cleaning, and self-disinfection) with
particular focus on SARS-CoV-2. The research reviews are, usually, focused on a
specific category of disinfection methods, and therefore they are limited. On the
contrary, a panoramic review with a wider focus, as the one here proposed, can be an
added value for operators in the sector and generally for the scientific community
Which Are the Main Surface Disinfection Approaches at the Time of SARS-CoV-2?
Among many guidelines issued by the World Health Organization to prevent contagion from novel coronavirus (SARS-CoV-2), disinfection of animate and inanimate surfaces has emerged as a key issue. One effective approach to prevent its propagation can be achieved by disinfecting air, skin, or surfaces. A thorough and rational application of an Environmental Protection Agent for disinfection of surfaces, as well as a good personal hygiene, including cleaning hands with appropriate products (e.g., 60\u201390% alcohol-based product) should minimize transmission of viral respiratory pathogens such as SARS-CoV-2. Critical issues, associated with the potential health hazard of chemical disinfectants and the ineffective duration of most of the treatments, have fostered the introduction of innovative and alternative disinfection approaches. The present review aims to provide an outline of methods currently used for inanimate surface disinfection with a look to the future and a focus on the development of innovative and effective disinfection approaches (e.g., metal nanoparticles, photocatalysis, self-cleaning, and self-disinfection) with particular focus on SARS-CoV-2. The research reviews are, usually, focused on a specific category of disinfection methods, and therefore they are limited. On the contrary, a panoramic review with a wider focus, as the one here proposed, can be an added value for operators in the sector and generally for the scientific community
Looking for the “Dream Catalyst” for Hydrogen Peroxide Production from Hydrogen and Oxygen
Abstract: The reaction between hydrogen and oxygen is in principle the simplest method to form
hydrogen peroxide, but it is still a “dream process”, thus needing a “dream catalyst”. The aim of this
review is to analyze critically the different heterogeneous catalysts used for the direct synthesis of
H2O2 trying to determine the features that the ideal or “dream catalyst” should possess. This analysis
will refer specifically to the following points: (i) the choice of the metal; (ii) the metal promoters
used to improve the activity and/or the selectivity; (iii) the role of different supports and their acidic
properties; (iv) the addition of halide promoters to inhibit undesired side reactions; (v) the addition
of other promoters; (vi) the effects of particle morphology; and (vii) the effects of different synthetic
methods on catalyst morphology and performance
Study of the Synthetic Approach Influence in Ni/CeO2-Based Catalysts for Methane Dry Reforming
This study focuses on the synthetic approach influence in morphostructural features and
catalytic performances for Ni/CeO2 catalysts. Incipient wetness impregnation, coprecipitation and
nitrate combustion were studied as catalyst preparation approaches, and the materials were then
tested at 700 C for methane dry reforming (MDR). The morphostructural properties of the materials
were deeply studied using several techniques, such as temperature programmed reduction (TPR),
to investigate reducibility and support-metal interaction, N2 physisorption to evaluate the porosity
and the surface area, scanning electron microscopy (SEM) and X-ray diffraction (XRD) to estimate Ni
dispersion, and temperature programmed oxidation (TPO) to identify the type and amount of coke
formed on catalysts’ surface after reaction. From the data obtained, coprecipitation turned out to be
the most suitable technique for this application because this catalyst was able to reach 70% of CO2
conversion and 30% methane conversion, with an H2 yield of 15% and 30% yield of CO at the end
of the 30 h test. Moreover, it was also the catalyst with the highest metal dispersion, the strongest
interaction with the support, and the lowest coke deposition
Titanium Dioxide-Based Nanocomposites for Enhanced Gas-Phase Photodehydrogenation
Light-driven processes can be regarded as a promising technology for chemical production
within the bio-refinery concept, due to the very mild operative conditions and high selectivity of some
reactions. In this work, we report copper oxide (CuO)-titanium dioxide (TiO2) nanocomposites to be
efficient and selective photocatalysts for ethanol photodehydrogenation under gas phase conditions,
affording 12-fold activity improvement compared to bare TiO2. In particular, the insertion method
of the CuO co-catalyst in different TiO2 materials and its effects on the photocatalytic activity were
studied. The most active CuO co-catalyst was observed to be highly dispersed on titania surface, and
highly reducible. Moreover, such high dispersion was observed to passivate some surface sites where
ethanol is strongly adsorbed, thus improving the activity. This kind of material can be obtained by the
proper selection of loading technique for both co-catalysts, allowing a higher coverage of photocatalyst
surface (complex-precipitation in the present work), and the choice of titania material itself. Loading
copper on a high surface area titania was observed to afford a limited ethanol conversion, due to its
intrinsically higher reactivity affording to a strong interaction with the co-catalyst
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