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This work presents a laboratory to help chemical-engineering students understand the basic concepts of corrosion. This laboratory has been performed since academic year 2011-2012 in the framework of the subject "Design of equipment and installations" for the third year of the Chemical Engineering Degree of the University of Castilla-La Mancha (Spain). It is based on calculating the corrosion rates of six different samples in order to evaluate the effects of the corrosion environment, the material of the sample, and the application of corrosion-prevention methods. The performance of the laboratory to enhance the teaching-learning methodology was evaluated by asking the students to answer a test before and after completing the laboratory. The results show that the laboratory improves the understanding of the students and also their confidence in their answers, although room for improvement was found in relation to the application of corrosion-prevention methods, for which corrective actions are proposed.

Alkaline water electrolysis powered by renewable energy sources is one of the most promising strategies for environmentally friendly hydrogen production. However, wind and solar energy sources are highly dependent on weather conditions. As a result, power fluctuations affect the electrolyzer and cause several negative effects. Considering these limiting effects which reduce the water electrolysis efficiency, a novel operation strategy is proposed in this study. It is based on pumping the electrolyte according to the current density supplied by a solar PV module, in order to achieve the suitable fluid dynamics conditions in an electrolysis cell. To this aim, a mathematical model including the influence of electrode-membrane distance, temperature and electrolyte flow rate has been developed and used as optimization tool. The obtained results confirm the convenience of the selected strategy, especially when the electrolyzer is powered by renewable energies.

A novel gas-phase electrocatalytic system based on a low-temperature proton exchange membrane (Sterion) was developed for the gas-phase electrocatalytic conversion of CO2 to liquid fuels. This system achieved gas-phase electrocatalytic reduction of CO2 at low temperatures (below 90 °C) over a Cu cathode by using water electrolysis-derived protons generated in-situ on an IrO2 anode. Three Cu-based cathodes with varying metal particle sizes were prepared by supporting this metal on an activated carbon at three loadings (50, 20, and 10 wt %; 50% Cu-AC, 20% Cu-AC, and 10% Cu-AC, respectively). The cathodes were characterized by N2 adsorption-desorption, temperature-programmed reduction (TPR), and X-ray diffraction (XRD) and their performance towards the electrocatalytic conversion of CO2 was subsequently studied. The membrane electrode assembly (MEA) containing the cathode with the largest Cu particle size (50% Cu-AC, 40 nm) showed the highest CO2 electrocatalytic activity per mole of Cu, with methyl formate being the main product. This higher electrocatalytic activity was attributed to the lower Cu-CO bonding strength over large Cu particles. Different product distributions were obtained over 20% Cu-AC and 10% Cu-AC, with acetaldehyde and methanol being the main reaction products, respectively. The CO2 consumption rate increased with the applied current and reaction temperature. [ABSTRACT FROM AUTHOR]

The stability testing of three different synthesized PtxSn1 − x/C anodic catalysts has been demonstrated for the renewable generation of hydrogen via the electrochemical reforming of ethanol in a proton exchange membrane (PEM) electrolysis cell. Three Pt-Sn anodic catalysts with different nominal Pt:Sn ratios of 60:40, 70:30, and 80:20 atomic (at.) % were synthetized and characterized by the means of electrochemical tests and XRD. Among them, the Pt-Sn anodic catalyst with 70:30 at. ratio showed the highest electrochemical active surface area (ECSA) and highest electrochemical reforming activity, which allowed the production of pure H2 with the lowest electrical energy requirement (below 23 kWh·kgH2−1). The stability of the system was also demonstrated through a long-term chronopotentiometry experiment of 48 h in duration. The potential for practical use and coupling this technology with renewable solar energy, a number of cyclic voltammetry tests (with a low scan rate of 0.19 mV·s−1) were also carried out. These experiments were performed by simulating the electrical power produced by a photovoltaic cell. This test showed good stability/reproducibility of the MEA and, hence, a suitable integration between the two technologies for the sustainable energy storage in the form of hydrogen.ᅟGraphical Abstract [ABSTRACT FROM AUTHOR]