An ammonium tetrathiomolybdate (ATTM) catalyst precursor is synthesized and then thermally decomposed at different temperatures in N 2 or H 2 atmosphere. Characterization of the resulting compounds by powder X-ray diffraction (XRD) and surface area analysis indicates the formation of MoS 2 -2H with a surface area of 5-9 m 2 /g. When ATTM is treated with cetyltrimethylammonium chloride and then decomposed in N 2 at 723 K, the resulting material has a surface area nearing 200 m 2 /g. If treatment also includes hydrazine, the surface area of the resulting MoS 2 -2H reaches 215 m 2 /g. Analysis by XRD and electron microscopy shows a noticeable dispersion in the layers of the resulting MoS 2 . The catalytic activity of the materials is tested in a batch reactor for cyclohexene hydrogenation, where the highest activity sulfides are those obtained by thermal decomposition of the chemically treated precursors in N 2 .

The synthesis of gold nanoparticles (Au-NPs), using Pluronic Ⓡ P103 as soft template to design tuned hybrid gold/P103 nanomaterials, is reported here. The effect of the concentration of P103 and the synthesis temperature on the growth, size, and morphology of Au-NPs were studied. The rheological properties of these hybrid nanomaterials at different measured temperatures were studied as well. By increasing the concentration of P103, the micelles progressively grew due to an increase in the number of surface cavities. These cavities came together causing large nucleation centers and developing larger Au-NPs. The synthesis temperature was varied to induce significant dehydration of the P103 micelles. Below the cloud point temperature micelles underwent distinct changes related to spherical-to-polymer-like micelles transitions. Two nanostructures were formed: (1) small Au-NPs arranged on the surface of micelles, which acted as soft templates, and (2) large and independent Au-NPs. Above the cloud point temperature, Au-NPs were related to the shape and size of the P103 micellar aggregates. Rheological measurements showed that viscosity was sensitive to the concentration of P103. Also, it was demonstrated that synthesis temperature had a considerable influence on viscosity of the produced nanomaterials.

Dilute aqueous solutions of triblock copolymer Pluronic P103 were used to synthesize silver nanoparticles (Ag-NPs) by chemical reduction of silver nitrate (AgNO3) with sodium borohydride (NaBH4). This copolymer was used as a structural agent since monomers act as a stabilizer and micelles act as nanoreactors for nucleation and growth of Ag-NPs. The growth of the nanoparticles (NPs) was monitored by UV-visible spectroscopy on the basis of measuring surface plasmon resonance absorption over a temperature range of 25 to 70°C. Shape and size of hybrid silver/P103 nanomaterials were tuned by varying the micellar structure of Pluronic P103 using a simple synthesis procedure. Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM) were used to study the size and shape of the hybrid nanomaterials. It was observed that Ag-NPs synthesized without Pluronic P103 at 25°C exhibited a great variety of sizes. However, when Pluronic P103 was used below its critical micellar concentration (CMC), spherical-shaped Ag-NPs with uniform size were formed, suggesting that the copolymer had a stabilizing effect. On the other hand, when Ag-NPs were prepared with Pluronic P103 above the CMC, NPs with similar sizes as the micelles were detected, suggesting that the copolymer functioned as a nanoreactor. Furthermore, as temperature reached 35°C, oval-shaped micelles were formed and small NPs were incorporated into the crown of the micelles. Independent Ag-NPs were not observed since they used the surface of the micelles as a soft template. Therefore, it was possible to obtain tiny Ag-NPs with homogeneous size.

Two series of molybdenum carbides are prepared from MoO 3 by temperature programmed reduction (TPR), differing in feed gas composition (20 and 40% CH 4 /H 2 ). The heating ramp consists of two steps, one from ambient temperature to 973 K, at a rate of 10 K/min; the second from 973 K up to the final temperature (1023, 1073, 1123, 1173 K), at a rate of 0.5 K/min. The Mo 2 C (hcp) phase is identified for the series prepared with 20% CH 4 /H 2 at different temperatures, with surface areas between 20 and 27 m 2 /g. Also found is a mix of the MoC and Mo 2 C (hcp) phases for the series prepared with 40% CH 4 /H 2 at temperatures above 1023 K, with surface areas between 9 and 19 m 2 /g. Both series of catalysts reach 100% conversion of cyclohexene in 5 h or less, with those catalysts prepared with a 40% CH 4 /H 2 gas mix reaching maximum conversion in the least time. Catalysts are compared to a commercial molybdenum carbide reagent as a reference.

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