Roberto Fiorenza

Au–Ag/CeO2 and Au–Cu/CeO2 Catalysts for Volatile Organic Compounds Oxidation and CO Preferential Oxidation

Oxidation of volatile organic compounds (VOC) and preferential oxidation of CO in the excess of H2 (CO-PROX) were investigated over mono and bimetallic Au–Ag/CeO2 and Au–Cu/CeO2 catalysts. For the oxidation of VOC (2-propanol, ethanol and toluene) Au/CeO2 was the most active catalyst for the combustion of alcohols to CO2, Ag/CeO2 gave the best performance in the toluene total oxidation, Au–Ag/CeO2 and Au–Cu/CeO2 showed the highest selectivity to partial oxidation products. For CO-PROX Au–Ag/CeO2 and Au–Cu/CeO2 samples exhibited higher CO2 yield at low temperature than monometallic ones. The improved performance of bimetallic catalysts were accounted for an enhancement of surface ceria oxygens mobility caused by the addition of Ag or Cu to Au/CeO2 and involved in both investigated reactions. This effect was more evident on Au–Ag/CeO2 where a strong Au–Ag interaction occurred with formation of Au–Ag alloy or linked monometallic nanoparticles.Graphical Abstract

Photoactivity of hierarchically nanostructured ZnO–PES fibre mats for water treatments

A brush-like ZnO nanorods shell is grown by Chemical Bath Deposition on electrospun Zn(Ac)2 doped polyethersulfone fibres. The obtained mats are water resistant and photocatalytically active, thus resulting suitable for applications in water purification. The used procedure is simple, cost-effective and scalable to large volumes. The use of supported ZnO nanostructures onto fibrous mats paves the way to easily reusable photocatalyst that benefits the high surface area of nanostructures and limits the drawbacks associated to the use of nanoparticles and nanopowders (i.e. water turbidity, irradiation efficiency and photocatalyst recover), thus resulting suitable for use in membrane technology.

Laser processing of TiO2 colloids for an enhanced photocatalytic water splitting activity.

We have measured the photocatalytic water splitting activity of several titania colloids, modified by nanosecond pulsed laser irradiation. Photocatalysis has been tested using UV and visible light. We have found that laser irradiation increases the hydrogen production efficiency up to a factor of three for anatase, rutile and P25. A hydrogen production rate as high as 30mmolg-1h-1 has been obtained with good stability, tested by repeated runs. The chemical and morphological properties of the nanoparticles have been studied by electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy, showing that laser irradiation promotes the formation of disordered surface state and lattice distortion which could be responsible for the observed enhanced photocatalytic activity.

Prediction of ionic liquid's heat capacity by means of their in silico principal properties

The in silico principal properties (PPs) of ionic liquids (ILs), derived by means of the VolSurf+ approach, were used to develop a Partial Least Squares (PLS) model able to find a quantitative correlation among IL descriptors (accounting for both cationic and anionic structural features) and heat capacity values, providing affordable predictions validated by experimental Cp measurements for an external set of ILs. In silico predictions allowed the selection of a limited number of structurally different ILs with similar Cp values, providing the possibility to select an optimal IL according to efficiency, as well as to environmental and economic sustainability. The present general procedure, using readily available descriptors for above 8000 ILs and adopting an accessible statistical procedure such as PLS, could be extended to other QSPR models.