Desaleació química d’hidròxids dobles laminars

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2021, Tutores: Teresa Andreu Arbella, Maria Sarret PonsLayered double hydroxides (LDH) are a family of materials with a variety of uses. Recently nickel based LDH have been studied for its properties as electrocatalysts for the water splitting reaction. In this work we will study if the addition and the latter removal of aluminium into the LDH structure improves the material properties as oxygen evolution catalyst. The LDH has been synthesized in three different metal combinations (nickel, nickel-iron and nickel-molybdenum) over a nickel foam support with a hydrothermal method. Both the structural and electrochemical properties of the material have been studied. Moreover, we studied an alternative method to deposit the LDH over the support with different grades of success. In the end, this study shows that only the metal combination of nickel and iron has the potential to become a useful electrocatalyst, and the removal of aluminium from a DLH does not make a better electrocatalyst compared with the non-aluminium counterpar

Effect of Thermal Treatment on Nickel-Cobalt Electrocatalysts for Glycerol Oxidation

Nickel-cobalt electrocatalysts with atomic ratios of 2 : 1 and 1 : 2 were synthesized on nickel foam (NF) substrates by cathodic electrodeposition, further evaluating the performance of the pristine and thermally-treated materials as anodes for glycerol oxidation in alkaline medium. The electrodes were characterized by cyclic and linear sweep voltammetry at alkaline pH, showing an indirect oxidation of glycerol mediated by the metal oxyhydroxides. Under the selected conditions, a favourable potential window of 0.2 V upon comparison of water and glycerol oxidation was found. In addition, the increase in nickel content and the thermal treatment enhanced the anode polarization. After galvanostatic electrolysis at 10 mA cm−2, the products were analysed by HPLC, formate ion being the primary product, with a faradaic efficiency (FE) higher than 70 % in most cases. Both the FE to formate and the glycerol conversion were substantially enhanced using the thermally-treated anodes, whereas the effect of the Ni/Co ratio on these two parameters did not follow a clear trend

Coupling glycerol oxidation reaction using Ni-Co foam anodes to CO2 electroreduction in gas-phase for continuous co-valorization

Electrocatalytic reduction of CO2 is a promising alternative for storing energy and producing valuable products, such as formic acid/formate. Continuous gas-phase CO2 electroreduction has shown great potential in producing high concentrations of formic acid or formate at the cathode while allowing the oxygen evolution or the hydrogen oxidation reactions to occur at the anode. It is advantageous to use a more relevant oxidation reaction, such as glycerol which is a plentiful by-product of current biodiesel production process. This work successfully manages to couple the glycerol oxidation reaction with continuous gas-phase CO2 electroreduction to formate with the implementation of Ni-Co foam-based anodes. The MEA-electrolyzer developed can achieve significantly high formate concentrations of up to 359 g L-1 with high Faradaic efficiencies of up to 95%, while also producing dihydroxyacetone at a rate of 0.434 mmol m−2 s−1. In comparison with existing literature, this represents an excellent trade-off between relevant figures of merit and can remarkably contribute to a future implementation of this coupled electrochemical system approach at larger scales.The authors gratefully acknowledge financial support through projects PID2019-108136RB-C31, PID2019-108136RB-C32 and PID2019-108136RB-C33, PID2020-112845RB-I00, TED2021–129810B-C21 and PLEC2022-009398 (MCIN/AEI/10.13039/501100011033 and Unión Europea Next GenerationEU/PRTR). This project has received funding from the European Union’s Horizon Europe research and innovation programme under grant agreement No 101118265​

Coupling glycerol oxidation reaction using Ni-Co foam anodes to CO2 electroreduction in gas-phase for continuous co-valorization

Electrocatalytic reduction of CO2 is a promising alternative for storing energy and producing valuable products, such as formic acid/formate. Continuous gas-phase CO2 electroreduction has shown great potential in producing high concentrations of formic acid or formate at the cathode while allowing the oxygen evolution or the hydrogen oxidation reactions to occur at the anode. It is advantageous to use a more relevant oxidation reaction, such as glycerol which is a plentiful by-product of current biodiesel production process. This work successfully manages to couple the glycerol oxidation reaction with continuous gas-phase CO2 electroreduction to formate with the implementation of Ni-Co foam-based anodes. The MEA-electrolyzer developed can achieve significantly high formate concentrations of up to 359 g L-1 with high Faradaic efficiencies of up to 95%, while also producing dihydroxyacetone at a rate of 0.434 mmol m−2 s−1. In comparison with existing literature, this represents an excellent trade-off between relevant figures of merit and can remarkably contribute to a future implementation of this coupled electrochemical system approach at larger scales.The authors gratefully acknowledge financial support through projects PID2019-108136RB-C31, PID2019-108136RB-C32 and PID2019-108136RB-C33, PID2020-112845RB-I00, TED2021–129810B-C21 and PLEC2022-009398 (MCIN/AEI/10.13039/501100011033 and Unión Europea Next GenerationEU/PRTR). This project has received funding from the European Union’s Horizon Europe research and innovation programme under grant agreement No 101118265​

La Reflexió com a eina d’aprenentatge

L'aprenentatge de l'estudiant i la seva formació com a professional i com a persona han de ser els objectius fonamentals de tot ensenyament. Sovint el professorat capficat en la transmissió de coneixements i en l'assoliment del programa, descuida, inconscientment, una part fonamental del paper que ha de jugar en la formació dels seus estudiants. La reflexió sobre un mateix, sobre la societat que l'envolta i sobre el seu futur com a professional és una eina formativa que sovint no s'utilitza a les aules. En aquest treball es presenten diferents formes de promoure la reflexió com a eina d'aprenentatge i els resultats obtinguts en assignatures de llicenciatura, de grau i de màste