Different strategies for the immobilization of copper complexes with 1,10-phenanthroline (phen) using the phosphonate anchoring group were investigated to prepare robust and porous heterogeneous catalysts. Homoleptic and heteroleptic copper(I) complexes with phen bearing the bis(trimethylsiloxy)phosphoryl anchoring group (Pphen-Si) at different positions of the phen backbone were prepared and covalently incorporated into titania (TiO₂) xerogels by using the sol–gel process or grafted onto the surface of mesoporous TiO₂ (S_BET = 650 m² g⁻¹). Copper(I) bis(Pphen-Si) complexes were the only complexes that were successfully anchored onto the TiO₂ surface because the heterogenization was often accompanied by the undesirable dissociation of copper complexes. Hybrid materials based on copper(I) chelates with one phen ligand were obtained following a two-step procedure involving the immobilization of Pphen-Si chelators and their successive complexation with copper(I) ions. Porous material, Cu/6b/SM/A, displaying a BET surface area of 243 m² g⁻¹ and bearing 0.57 mmol g⁻¹ of the complex was synthesized according to this approach. Excellent catalytic performance of the reusable Cu/6b/SM/A material in the Sonogashira-type coupling and the Huisgen 1,3-dipolar cycloaddition was also demonstrated. This solid represents the first example of mesoporous TiO₂-supported transition metal catalysts.

This work investigates the influence of spark plasma sintering (SPS) parameters on the microstructure and mechanical properties of consolidated aluminum powders processed by high-energy ball milling under an air atmosphere. Sintering was performed under vacuum at various temperatures ranging from 550 °C to 625 °C and under pressures between 50 and 100 MPa. The particle size, crystallite size, and microstructure of the powders and the consolidated pellets were analyzed using laser granulometry, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Archimedes’ density measurements. Mechanical properties were evaluated via Vickers microhardness, nanoindentation, and tribological testing. For comparison, unmilled aluminum powders were also consolidated and characterized. After 46 h of milling, the aluminum crystallite size was reduced from 74 nm to 68 nm. The sample’s density increased with higher sintering temperature and pressure. The aluminum sintered at 600 °C and 100 MPa after 46 h of milling exhibited the highest microhardness (187.5 HV). Nanoindentation tests were conducted to characterize different microstructural regions formed after SPS, revealing two distinct zones: one hard and one soft. The tribology results revealed that the SPS-consolidated samples of milled powders exhibited a reduction of 50% in specific wear rate and a reduction of 20% in the coefficient of friction compared to the SPS-sintered samples of unmilled powders.