Loading and promoter effects on the performance of nitrogen functionalized graphene nanosheets supported cobalt Fischer-Tropsch synthesis catalysts

The effects of nitrogen functional groups on graphene surface and also the effects of cobalt loading and ruthenium promoter on the performance of nitrogen functionalized graphene nanosheets (N-GNS) supported cobalt catalysts in Fischer–Tropsch synthesis (FTS) are investigated. A 15 wt% Co/PGNS catalyst, a series of Co/N-GNS (15–30 wt% loading) and ruthenium promoted catalysts (25 wt% Co,0.5 wt% Ru/N-GNS and 25 wt% Co,0.5 wt% Ru/PGNS) were prepared by impregnation method. The purified GNS and functionalized GNS and all catalysts were characterized by Raman spectroscopy, FTIR, SEM, EDS, ICP, BET, TEM, XRD and TPR. The catalysts assessed in FTS in a fixed bed micro-reactor at 220 °C, 1.8 Mpa and H 2 /CO ratio of 2. Functionalization of GNS shifted the TPR reduction peaks to lower temperature, increased the dispersion of cobalt particles and increased the percentage CO conversion from 70.6% to 74.5%. Increasing the cobalt loading resulted in increasing the average cobalt cluster size, improvements in the reducibility of Co 3 O 4 . The maximum FTS activity for N-GNS supported catalyst is achieved at 30 wt % cobalt loading. The C 5 + selectivity for the 30 wt % cobalt catalyst was higher than that of the 15 wt % Cobalt catalyst. Addition of 0.5 wt%Ru increased the FTS rate (gCH/(gcat·h)) from 0.377 to 0.412 and the liquid products selectivity from 86.5% to 91.2%. © 2019 Hydrogen Energy Publications LL

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

FOTOCATALIZZATORI FISSATI MEDIANTE LE FINITURE TRADIZIONALI DEL MARMORINO: UNA STRATEGIA ECOLOGICA TRA CHIMICA E RESTAURO PER RENDERE PIÙ PULITE LE NOSTRE CITTA’

Nella tradizione costruttiva veneziana del rivestimento ad intonaco in marmorino è noto che le finiture superficiali erano basate su particolari lavorazioni di pressatura e lamatura e sulla stesura di additivi di protezione organici (sapone, cera, olio di lino) in modo da rendere le superfici molto resistenti alle aggressioni ambientali. Negli interventi di restauro sulle facciate dell’edilizia storica, nei casi in cui si eseguono integrazioni di marmorini esistenti o rifacimenti estesi, è possibile operare con quelle sostanze protettive, in particolare calce e sapone, che riprendono le tecniche del passato e offrono durabilità simili a quelle antiche. Questa possibilità di lavorare con sostanze protettive fissate in superficie ha offerto l’occasione di sperimentare l’aggiunta di prodotti eco-compatibili e incolori che forniscano anche un miglioramento delle condizioni ambientali. Infatti, sono stati eseguiti una serie di campioni utilizzando materiali nanostrutturati multifunzionali che possono degradare i principali inquinanti ambientali organici e inorganici (NOx, VOC) mediante fotocatalisi, oltre a ridurre gli attacchi batterici e conferire proprietà autopulenti. Sfruttando le caratteristiche leganti della calce e del sapone impiegati per rinforzare i marmorini preesistenti, allo stato secco, o i marmorini di nuova esecuzione, con stesure superficiali a fresco, si sono studiati gli effetti di due fotocatalizzatori basati sul biossido di titanio e sull’ossido di zinco, entrambi considerati in una versione commerciale e in una versione sintetizzata in laboratorio. Per simulare il degrado superficiale è stato impiegato il blu di metilene come modello di inquinante organico in modo da valutare le proprietà fotocatalitiche dei materiali mediante analisi colorimetriche; inoltre sono stati caratterizzati i materiali con altre tecniche di laboratorio: diffrazione ai raggi X (XRD), fisisorbimento di azoto, microscopia elettronica a scansione (SEM) accoppiata ad analisi EDX (Energy Dispersive X ray). I migliori risultati sono stati ottenuti con il biossido di titanio commerciale e l’ossido di zinco sintetizzato in laboratorio applicati sfruttando la capacità legante del sapone. I risultati sono soddisfacenti e aprono un settore innovativo nel campo del restauro che trova nella chimica un supporto verso la biocompatibilità dei materiali impiegati anche per ridurre l’inquinamento presente nell’aria, oltre a ridurre gli attacchi batterici e conferire proprietà autopulenti