Hydrocracking of Heavy Vacuum Gas Oil with a Pt/H-beta−Al 2 O 3 Catalyst: Effect of Zeolite Crystal Size in the Nanoscale Range

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A Combinatorial Approach for the Solution Deposition of Thin Films

Optimization of thin film deposition is often the limiting step in the discovery of new materials and device development. Over the years, high-throughput combinatorial methods were developed for the deposition of thin films from the gas phase. However, very few reports focused on combinatorial thin film deposition from solution. Here, we introduce a combinatorial approach for the deposition of thin films from solution. The flow deposition setup allows for simultaneously studying the effect of two critical parameters, deposition time and deposition temperature, on a single sample. As a proof of concept, we demonstrate the solution deposition of PbS thin films, which resulted in a library of 25 deposition condition combinations on a single GaAs (100) substrate. X-ray diffraction and scanning electron microscopy combined with focused ion beam cross-sectional sample preparation confirmed the formation of high-quality PbS films and showed the morphology evolution as a function of these two deposition parameters. This method can be easily adapted for cost-effective and rapid combinatorial studies of a large variety of solution-deposited thin film materials

Effect of silica wall microporosity on the state and performance of TiO₂ nanocrystals in SBA-15 matrix

TiO2 guest phase was incorporated by internal hydrolysis (IH) method inside SBA-15 mesostructured silica matrices with high and low microporosity (14.2% and 4.7% of microporous pore volume, respectively). TiO2 phase was located inside the SBA-15 pores in form of small crystals with anatase structure without blocking the mesopores over wide range of loadings (8–50 wt%) (N2 sorption, HRTEM and XRD). In the highly microporous SBA-15 (SBA-15-HM), the crystallization of titania anatase phase was detected at 150 °C due to initiation of the crystallization process in the micropores. This is supported by the fact that the crystallization was significantly delayed and started at 350 °C inside the SBA-15 with low microporosity (SBA-15-LM). Therefore, it was proposed that the formation of nanocrystalline titania in SBA-15 micropores initiates the nucleation stage thus enhancing the crystallization process of titania in the mesopores. Furthermore, micropores enhanced the dispersion of TiO2 phase. As a result, TiO2/SBA-15-HM adsorbed more vanadia than TiO2/SBA-15-LM. The catalytic activity in selective catalytic reduction (SCR) of NO with ammonia was proportional to the vanadia content. Thus, V2O5-TiO2/SBA-15-HM catalysts were more active than V2O5–TiO2/SBA-15-LM at all TiO2 loadings due to the higher vanadia content in TiO2/SBA-15-HM than in TiO2/SBA-15-LM. These results show that SBA-15 wall microporosity strongly affects the crystallization, state and performance of the guest phase confined in mesoporous channels of silica matrix