Search results for " added value"
showing 5 items of 5 documents
Heterogeneous photocatalytic aqueous succinic acid formation from maleic acid reduction
2022
This study reports the anaerobic reduction of maleic acid to succinic acid in aqueous dispersion of different TiO2 based photocatalysts. Some home prepared and commercial solids containing different polymorphic phases of TiO2 and loaded with Pt and Ru were compared at different acidic pHs. The aim of the work was to verify the feasibility of the process and to determine the best samples and the optimal experimental conditions of the reaction. The best selectivity towards succinic acid was 23.2 % at 70 % of maleic acid conversion. Fumaric acid was also formed as another high added value compound, and its quantity was related to the experimental conditions and the photocatalyst used.
Formation of high added value chemicals by photocatalytic treatment of biomass
2020
The depletion of fossil fuel requires the search for alternative renewable feedstock and environmentally friendly methods for the production of high value-added compounds and fuels. In this context, the efficient use of biomass has emerged as a significant research field as it represents an alternative green and renewable carbon source. Various technologies have been explored for this purpose and heterogeneous photocatalysis represents a valid alternative to the catalytic methods since it can be carried out under mild experimental conditions without the addition of harmful oxidizing agents. Different biomass components have been used as the starting materials, and many valuable chemicals h…
Solar heterogeneous photocatalysis for high added value molecules production
A facile way to synthesize noble metal free TiO2 based catalysts for glycerol photoreforming
2023
In this work anaerobic heterogeneous photocatalytic solar/UV light reforming of glycerol in aqueous media was performed with Pt-photodeposition and noble metal free modified TiO2 photocatalysts prepared through ball milling, a very simple and cheap coupled catalyst preparation method. Different amounts of Cu2O or 3% CuO were loaded on TiO2 using ball milling and during each run glycerol conversion, hydrogen and CO2 formed in the gas phase and 1,3-dihydroxyacetone (DHA) and glyceraldehyde (GA) in the liquid phase were determined. The results were compared with the aim to verify the effectiveness of Cu2O in replacing Pt. Using noble metal free photocatalysts, 33% glycerol conversion, 10.3% an…
La valutazione e l’autovalutazione delle scuole italiane
2016
La comprensione del significato sociale della valutazione di tutte le scuole italiane, avviata con l’a. s. 2014-15 lungo un percorso triennale articolato in quattro fasi, migliora se si considerano le premesse e i preparativi dei venti anni precedenti. Sono scandite le tappe di avvicinamento alla prima valutazione sistematica della scuola italiana che, con tutti i suoi limiti, costituisce un’autentica inversione di rotta rispetto al livellamento verso il basso delle prestazioni, una deformazione del principio dell’uguaglianza, cui si tendeva per una serie di meccanismi economici, sindacali e partitici, che la governance istituzionale non riesce ancora a contrastare efficacemente. Sono indic…