Valerio Molinari

Sponge‐like Nickel and Nickel Nitride Structures for Catalytic Applications

A safe and simple method to fabricate air-stable nickel nitride and nickel embedded in carbon and nitrogen matrix, with high surface area for catalytic applications, is presented. The new synthesis employs molten inorganic salts as the reaction media. The use of salt melt opens new possibilities for safe, simple, and cheap synthesis of metal nitrides and metals for energy-related applications.

An integrated strategy for the conversion of cellulosic biomass into γ-valerolactone

An integrated method for the production of γ-valerolactone from cellulosic biomass is presented here. A combination of acidic water hydrolysis of the biomass followed by extraction with methyltetrahydrofuran is used to generate a levulinic acid feed, which is further hydrogenated into the platform chemical γ-valerolactone using RANEY® nickel as a catalyst.

Easy Access to Ni3N– and Ni–Carbon Nanocomposite Catalysts

In the search for alternative materials to current expensive catalysts, Ni has been addressed as one of the most promising and, on this trail, its corresponding nitride. However, nickel nitride is a thermally unstable compound, and therefore not easy to prepare especially as nanoparticles. In the present work, a sol-gel-based process (the urea glass route) is applied to prepare well-defined and homogeneous Ni3N and Ni nanoparticles. In both cases, the prepared crystalline nanoparticles (∼25 nm) are dispersed in a carbon matrix forming interesting Ni3N- and Ni-based composites. These nanocomposites were characterised by means of several techniques, such as XRD, HR-TEM, EELS, and the reaction mechanism was investigated by TGA and IR and herein discussed. The catalytic activity of Ni3N is investigated for the first time, to the best of our knowledge, for hydrogenation reactions involving H2, and here compared to the one of Ni. Both materials show good catalytic activities but, interestingly, give a different selectivity between different functional groups (namely, nitro, alkene and nitrile groups).

A high‐throughput composite catalyst based on Nickel carbon cubes for the hydrogenation of 5‐hydroxymethylfurfural to 2,5‐dimethylfuran

A high‐throughput composite catalyst is prepared from porous carbon with an unconventional nanocube morphology decorated with nickel nanoparticles. Owing to the advantageous properties of the designed carbon support, the composite combines a high surface area and a hierarchical pore structure with high functionality. Furthermore, the regularly shaped nanocubes allow for a good packing of a fixed‐bed flow reactor, in which the internal transport pores cannot be blocked and stay open for efficient column performance. The composite is employed as a catalyst in the hydrogenation of 5‐hydroxymethylfurfural (HMF) to 2,5‐dimethylfuran (DMF), showing good catalytic performance and overcoming the conventional problem of column blocking.

Tough High Modulus Hydrogels Derived from Carbon-Nitride via an Ethylene Glycol Co-solvent Route

High concentration formulations of graphitic carbon nitride (g-CN) are utilized as photoinitiator and reinforcer for hydrogels. In order to integrate significant amounts of g-CN, ethylene glycol (EG) is employed as a co-solvent for the gel formation, which enables stable dispersion of up to 4 wt% g-CN. Afterwards, EG can be removed easily via solvent exchange to afford pure hydrogels. The diverse gels possess remarkably high storage moduli (up to 650 kPa for gels and 720 kPa for hydrogels) and compression moduli (up to 9.45 MPa for 4 wt% g-CN EG gel and 3.45 MPa for 4 wt% g-CN hydrogel). Full recovery without energy loss is observed for at least 20 cycles. Moreover, gel formation can be performed in a spatially controlled way utilizing photomasks with desired shapes. Therefore, the suggested method enables formation of hybrid gels by optical lithography with outstanding mechanical properties very similar to natural cartilage and tendon, and opens up opportunities for future applications in photocatalysis, additive manufacturing of biomedical implants and coating materials.