R. Huirache-Acuña

SBA-15 Mesoporous Silica as Catalytic Support for Hydrodesulfurization Catalysts—Review

SBA-15 is an interesting mesoporous silica material having highly ordered nanopores and a large surface area, which is widely employed as catalyst supports, absorbents, drug delivery materials, etc. Since it has a lack of functionality, heteroatoms and organic functional groups have been incorporated by direct or post-synthesis methods in order to modify their functionality. The aim of this article is to review the state-of-the-art related to the use of SBA-15-based mesoporous systems as supports for hydrodesulfurization (HDS) catalysts.

Sol Gel-Derived SBA-16 Mesoporous Material

The aim of this article is to review current knowledge related to the synthesis and characterization of sol gel-derived SBA-16 mesoporous silicas, as well as a review of the state of the art in this issue, to take stock of knowledge about current and future applications. The ease of the method of preparation, the orderly structure, size and shape of their pores and control, all these achievable through simple changes in the method of synthesis, makes SBA-16 a very versatile material, potentially applicable in many areas of science and molecular engineering of materials.

Synthesis of MoS2 nanorods and their catalytic test in the HDS of dibenzothiophene

Partially sulfided nanostructures were synthesized by direct sulfurization of alpha-MoO(3) nanorods using a mixture of H(2)S/H(2), 15 vol%, at several temperatures (400, 500, 600, 700, and 800 degrees C). These materials were tested as catalysts in the hydrodesulfurization (HDS) of dibenzothiophene (DBT) and characterized by specific surface areas using the expression developed by Brunauer, Emmett, and Teller (BET equation), x-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The TEM images show a gradual evolution from a smooth surface to a rough material, presenting some type of holes all over the particles, but keeping their rod-like structure throughout sulfidation. The results of evaluating the catalysts in the HDS of DBT showed that the best temperature for sulfidation is 500 degrees C. In all samples, a higher selectivity for hydrogenation over sulfur removal was observed.

Improved hydrothermal synthesis of MoS2 sheathed carbon nanotubes

MoS2 sheathed carbon nanotubes have been successfully synthesized using a hydrothermal route under controlled conditions. The resultant material was studied by XRD, EDS, HRTEM, and Raman spectroscopy. Advantages of the preparation presented here compared to other methods are: a) lower reaction temperature, b) high yield of sheathed nanotubes including ends and full body, c) simple process with non-toxic materials, and d) no damage inflicted to nanotubes.

Synthesis and Characterization of Hydroxyapatite-Based Nanostructures: Nanoparticles, Nanoplates, Nanofibers and Nanoribbons

Material science is taking an increasing important role in bioengineering and biomedical sciences, aiming to develop new systems and materials capable of adapting to the highly demanding environment of a living organism. One of those materials, Hydroxyapatite (HAp), is the principal calcium orthophosphate present in the mineral phase of bone.

Synthesis of iron sulfide films through solid–gas reaction of iron with diethyl disulfide

Iron sulfide films were synthesized by the solid–gas reaction of diethyl disulfide on iron foils in the temperature range of 658–768 K using a microbalance, where the film growth kinetics followed Deal–Grove behavior. Analysis of the films by X-ray photoelectron and Raman spectroscopies as well as X-ray diffraction and scanning electron microscopy analysis revealed the formation of combined FeS/FeS2 (troilite/pyrite) films with a sheet-like morphology at low temperatures and only FeS (troilite) films with granular morphology at higher temperatures. GRAPHICAL ABSTRACT

Overview of Phosphorus Effect in Molybdenum-Based Hydrotreating Catalysts Supported on Ordered Mesoporous Siliceous Materials

This chapter presents an overview of the literature on the effect of phosphorus modification of ordered mesoporous silica (OMS) such as MCM-41, HMS, SBA-15, and SBA-16 to be used as supports for hydrotreating catalysts based on transition metal sulfides (TMS). The influence of the support modification with variable quantities of phosphorus on the performance for hydrodesulfurization (HDS) and hydrodenitroge‐ nation (HDN) reactions is outlined and discussed considering the changes in the structural and textural properties (SBET), acidity, reducibility, etc., of the substrate brought about by phosphorus incorporation.

Crystallographic studies through HRTEM and XRD of MoS2nanostructures

E. Rivera-Muñoz, R. Huirache-Acuña, B. Millán-Malo, R. Nava, B. Pawelec, C. Loricera Universidad Nacional Autonoma de Mexico, Centro de Fisica Aplicada y Tecnologia Avanzada, Queretaro, Mexico., Universidad Michoacana de San Nicolas de Hidalgo, Facultad de Ingenieria Quimica, Morelia, Mexico., Universidad Autónoma de Querétaro, Division de Investigacion y Posgrado Facultad de Ingenieria, Queretaro, Mexico., Consejo Superior de Investigaciones Cientificas, Instituto de Catalisis y Petroleoquímica, Madrid, Spain.