Several methods have been developed and applied in recent years in the characterization of the structure of microporous materials, in general, and of pillared clays, in particular. In the present article, the latest results obtained in the control of the microstructure developed in alumina‐pillared clays and various approaches used to the evaluation of the porosity of these materials are reviewed. These include the control of the microstructure developed in pillared clays by adjusting the several parameters involved in the synthesis process, and the evaluation of the porosity of pillared clays. Emphasis is given to the methods to evaluate the pore size and pore size distribution (PSD) of these materials. Two separate sections are devoted to review mathematical modeling studies and ¹²⁹Xe NMR spectroscopy of physisorbed Xe to investigate the microporous structural properties of these materials.

The use of biofuels offers advantages over existing fuels because they come from renewable sources, they are biodegradable, their storage and transport are safer, and their emissions into the atmosphere are lower. Biomass is one of the most promising sustainable energy sources with a wide variety of organic materials as raw material. Chemical, biochemical, and thermochemical methods have been proposed to obtain biofuels from raw materials from biomass. In recent years, a thermochemical method that has generated great interest is hydrothermal liquefaction. In this paper, a brief review of the main sources for liquid biofuels and the synthesis processes is presented, with special emphasis on the production of biofuels using hydrothermal liquefaction by using waste generated by human activity as raw material.

Batch sorption experiments were performed to study the adsorption of six emerging pollutants from aqueous solutions using a commercial granular activated carbon as adsorbent. Caffeine, clofibric acid, diclofenac, gallic acid, ibuprofen and salicylic acid were selected as representative contaminants. The activated carbon was characterized by nitrogen adsorption at 77 K, and through the determination of point of zero charge. The effects of several operational parameters, such as pH, initial concentration of organic molecules, mass of adsorbent and contact time, on the sorption behaviour were evaluated. The contact time to attain equilibrium for maximum adsorption was found to be 40 min. The kinetic data were correlated to several adsorption models, and the adsorption mechanism found to follow pseudo-second-order and intraparticle-diffusion models with external mass transfer predominating in the first 15 min of the experiment. The equilibrium adsorption data were analysed using the Freundlich, Langmuir and Toth isotherm equation models. The similar chemical structure and molecular weight of the organic pollutants studied to make the adsorption capacity of the activated carbon used very similar for all the molecules. GRAPHICAL ABSTRACT

Ni-based catalysts are highly efficient in methane-reforming processes. In the particular case of methane reforming in the presence of carbon dioxide, or dry reforming of methane (DRM), it is necessary to modify and control the initial properties of the catalyst to confer on it resistance to carbon deposition in particular, and to sintering of the Ni metal particles. In this regard, catalytic supports and promoters of different natures have been proposed. Likewise, the addition of small amounts of noble metals to avoid oxidation of the Ni active phase during the reforming reaction has been proposed. Catalyst preparation methods have also been identified as being of particular interest, since they can affect the structure of the Ni metal particles. In this review, the thermodynamic and kinetic aspects of the dry reforming of methane reaction are presented first. The most recent developments in synthetic methods (impregnation, sol-gel, co-precipitation, equilibrium deposition filtration, atomic layer deposition, non-thermal glow discharge plasma, multi-bubble sonoluminescence, “core-shell” structure) aimed at maximizing the dispersion and thermal resistance of Ni particles are then discussed and compared. The catalytic supports used to promote dispersion of the active metallic phase, the oxygen-storage capacity, and the metal/support interaction are also described. The review then addresses the fact that both the nature of the support and the addition of promoters and other metallic phases that modify the surface properties can control the interaction between the metal and the support, the electronic density of the active phase, and the degree of Ni reduction. Finally, new lines of research focused on the DRM process to make the reaction conditions milder and favor the process at low temperatures are also summarized.