15 research outputs found
Design of innovation in a technical subject
Copyright (2009) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
The following article appeared in AIP Conf. Proc. 1181, 738 (2009) and may be found at http://dx.doi.org/10.1063/1.3273695.The greatest motivation found in the teaching of the subject Mechanical Technology is the ability to speak to students about manufacturing technologies. The main objective of learning in this subject is a global vision of the manufacturing process, and its optimization in terms of applicability to the real world. The best way for students to learn these concepts is for the teacher to explain them with a more global view aimed at reaching a comprehensive vision with a high degree of detail.JuĂĄrez VarĂłn, D.; Peydro, MA.; Reig PĂ©rez, MJ.; Parres, F. (2009). Design of innovation in a technical subject. American Institute of Physics (AIP). doi:10.1063/1.3273695
Ir-Catalysed Nitrous Oxide (N2O) Decomposition:Effect of Ir Particle Size and MetalâSupport Interactions
The effect of the morphology of Ir particles supported on Îł-Al2O3, 8 mol%Y2O3-stabilized ZrO2 (YSZ), 10 mol%Gd2O3-doped CeO2 (GDC) and 80 wt%Al2O3â10 wt%CeO2â10 wt%ZrO2 (ACZ) on their stability on oxidative conditions, the associated metalâsupport interactions and activity for catalytic decomposition of N2O has been studied. Supports with intermediate or high oxygen ion lability (GDC and ACZ) effectively stabilized Ir nanoparticles against sintering, in striking contrast to supports offering negligible or low oxygen ion lability (Îł-Al2O3 and YSZ). Turnover frequency studies using size-controlled Ir particles showed strong structure sensitivity, de-N2O catalysis being favoured on large catalyst particles. Although metallic Ir showed some de-N2O activity, IrO2 was more active, possibly present as a superficial overlayer on the iridium particles under reaction conditions. Support-induced turnover rate modifications, resulted from an effective double layer [OÎŽââÎŽ+](Ir) on the surface of iridium nanoparticles, via O2â backspillover from the support, were significant in the case of GDC and ACZ
Study Of Changes In Viscosity Of Virgin And Recycled PCTA DS2010, Degradation Of This Material Due To Remaining At The Injection Temperature And Improvements In The Cleaning Of Capilliary Rheometers
HighâPressure Operando UVâVis MicroâSpectroscopy of Coke Formation in Zeoliteâbased Catalyst Extrudates during the Transalkylation of Aromatics
The performance of zeolite-based catalyst extrudates can be largely influenced by the choice of binder material. To investigate these binder effects in zeolite-based catalyst extrudates in more detail, high spatiotemporal resolution techniques need to be further developed and employed. In this work, we present a new methodology to investigate binder effects in catalyst extrudates at different reaction pressures using operando UV-vis diffuse reflectance (DR) micro-spectroscopy coupled with on-line gas chromatography. We have studied mm-sized zeolite H-ZSM-5-containing extrudates with either Al2O3 or SiO2 binder material, during the transalkylation of toluene with 1,2,4-trimethylbenzene at 450 °C and at a pressure of either 1 or 5 bar. Using this technique, it was revealed that the binder material significantly influenced catalyst deactivation at different reaction pressures. By subsequent mapping of the cross sections of the cylindrical catalyst extrudates using UV-vis micro-spectroscopy, it was shown that the SiO2-bound extrudate formed poly-aromatic coke molecules homogeneously throughout the entire extrudate, whereas for the Al2O3-bound extrudate a coke ring formed that moved inwards with increasing reaction time. Notably, the developed methodology is not limited to the transalkylation reaction, and can also be used to gain more insight into binder effects during a variety of important catalytic reactions