Intensification of X-ray diffraction peaks can be used to get information about doping, presence of vacancies, anisotropic nanostructures, or preferred orientation of crystals with largely exposed facets.

Sintering is an important issue in creating crystalline metal oxides with high porosity and surface area, especially in the case of high-temperature materials such as metal aluminates. Herein we report a rationally designed synthesis of metal aluminates that diminishes the surface area loss due to sintering. MeAl2O4 (Me = Ni, Co or Cu) supported on γ-Al2O3 with ultra-large mesopores (up to 30 nm) were synthesized through microwave-assisted peptization of boehmite nanoparticles and their self-assembly in the presence of a triblock copolymer (Pluronic® P123) and metal nitrates, fol-lowed by co-condensation and thermal treatment. The resulting materials showed the surface area up to 330 m2 g-1, and porosity up to 1.6 cm3 g-1, and very good thermal stability. The observed enhancement in their thermomechanical resistance is associated with the faster formation of the metal aluminate phases. The nanometer scale path-diffusion and highly defective interface of γ-alumina facilitate the counter-diffusion of Mex+ and Al3+ species, and further formation of the metal aluminate phase. Additionally, it is shown that the type of transition metal affects the pore size of the nanostructured metal oxide by shifting the decomposition temperature of the triblock copolymer. Overall, the synthesis strategy requires easy steps and readily available precursors, and promotes the formation of highly porous nanostructured oxides suitable for several applications such as catalysis and adsorption.

One-pot synthesis of nanostructured ternary oxides of Ni, Al, and Ti was designed and performed via evaporation induced self-assembly (EISA). For the purpose of comparison, analogous oxides were also prepared by the impregnation method. The resulting materials were applied in two catalytic reactions: steam reforming of ethanol (SRE) for H₂ production (subjected to prior activation with H₂) and ethanol dehydration (ED; used without prior activation), to in situ analyze carbon accumulation by ethylene depletion when ethanol interacts with acidic sites present on the support. Modification of Ni–Al mixed oxides with titania was shown to have several benefits. CO₂, NH₃, and propylamine sorption data indicate a decrease in the strength of acidic and basic sites after addition of titania, which in turn slowed down the carbon accumulation during the ED reaction. These changes in interactions between ethanol and byproducts with the support led to different reaction pathways in SRE, indicating that the catalysts obtained by EISA with titania addition showed higher ethylene selectivity and CO₂/CO ratios. The opposite was observed for the impregnated catalysts, which were less coke-stable during ED reactions and showed no ethylene selectivity in SRE. Carbon formed during ED reactions was shown to be thermodynamically less favorable and easier to decompose in the presence of titania. All catalysts studied displayed similar and high selectivities (∼80%) and yields (∼5.3 mol_H2/mol_ethanol) toward H₂, which place them among the most active and selective catalysts for SRE. These results indicate the importance of tailoring the support surface acidity to achieve high reforming performance and higher selectivity toward SRE, one of the key processes to produce cleaner and efficient fuels. For an efficient reforming process, the yield of byproducts is low but still they affect the catalyst stability in the long-run, thus this work may impact future studies toward development of near-zero coke catalysts.

Initially, in the synthesis of Cu–BTC MOFs some fraction of Cu was expected to be replaced with Mg to enhance its CO₂ adsorption properties.