Improvement of the detention mechanism of a car impulsed by a chemical reaction

Grado en Ingeniería Químic

Electroreduction of CO2: advances in the continuous production of formic acid and formate

The study of the electrochemical CO2 reduction to obtain formate (HCOO–) or formic acid (HCOOH) is receiving much attention as a promising technology. Since continuous–mode operation has become necessary for practical implementation of electrochemical CO2 reduction, recent years have seen a rapid increase in the number of research approaches focusing on this aspect. This Focus Review provides a unified discussion of the available studies on the continuous electroreduction of CO2 to HCOO–/HCOOH, considering the different important features of process design. Moreover, this paper quantitatively assesses the performance of different studies that involve continuous electrochemical reactors for converting CO2 to HCOOH/HCOO–, comparing relevant typically used figures of merit, including energy consumption. Although some relevant trade-offs have already been achieved, the simultaneous optimization of all the figures of merit remains a challenge. Finally, concluding remarks highlight the detected trends and discuss relevant aspects that will have to be tackled by future studies in this field.The authors acknowledge the financial support from the Spanish State Research Agency (AEI) through the projects PID2019-108136RB-C31 and PID2020-112845RB-I00 (MCIN/AEI/10.13039/501100011033)

Single-Pass Electrooxidation of Glycerol on Bismuth-Modified Platinum Electrodes as an Anodic Process Coupled to the Continuous CO2 Electroreduction toward Formate

CO2 electroreduction has emerged as a promising strategy for reducing emissions while simultaneously generating valuable products, particularly formic acid/formate. To further enhance the sustainability of this process, the traditional oxygen evolution reaction at the anode can be replaced by a more interesting reaction like glycerol oxidation to high value-added products, in a covalorization approach. In this study, the effect of the presence of a bismuth (Bi) atom supplier (Bi2O3 particles) in the anolyte solution during the glycerol electrooxidation process on platinum (Pt) electrodes coupled with the electroreduction of CO2 to formate is investigated for the first time, operating in a continuous mode with a single pass through the reactor. The results reveal that in the cathode, significant HCOO– production, with Faradaic efficiencies reaching 93%, and modest energy consumption of 208 kW h·kmol–1 were obtained in the continuous CO2 electroreduction to formate using Bi gas diffusion electrodes. On the other hand, in the anode, the presence of Bi2O3 particles leads to a significant alteration in the distribution of high-value-added oxidation products obtained. For instance, the anode demonstrates remarkable dihydroxyacetone (DHA) production of 283 μmol·m–2·s–1, surpassing the results obtained with the nonmodified Pt electrodes. The performance of this system offers a promising pathway for the simultaneous coproduction of high-value-added products from both CO2 and glycerol.The authors gratefully acknowledge the financial support through MCIN/AEI/10.13039/501100011033 projects PID2019-108136RB-C31 and PID2019-108136RB-C32

Coupling continuous CO2 electroreduction to formate with efficient Ni-based anodes

CO2 electroreduction to formic acid and formate has been focus of great research attention in the last years. Thus, considerable and relevant efforts have been accomplished in this field, mainly by operating with different types of catalysts and electrode configurations in the cathodic compartment. Still, Pt-based anodes, which are expensive and scarce, are typically the preferred materials to carry out the oxygen evolution reaction in alkaline medium. However, it is crucial to search for new materials of lower prices, with high stability, and good performances able to be competitive with traditional Pt-based electrodes. Hence, we study hand-made NiO-based anodes for the continuous CO2 electroreduction for formate in a filter press reactor with a single pass of the reactants through the electrochemical reactor. The use of the NiO-based anodes enhances the results obtained in previous studies with DSA/O2 anodes, combining excellent values of Faradaic Efficiency for formate of 100 %, and energy consumptions values close to only 200 kWh·kmol-1. In addition, employing Sustainion® as a binder in the fabrication of the anode results in a significant improvement in the durability, maintaining similar performance in terms of key metrics.Authors fully acknowledge the financial support received from the Spanish State Research Agency (AEI) through the projects PID2019-108136RB-C31 and PID2020-112845RB-I00 (AEI/10.13039/501100011033). We are also grateful for the Bi carbon-supported nanoparticles prepared and provided by the group of Prof. V. Montiel and Dr. José Solla-Gullón from the Institute of Electrochemistry of the University of Alicante. Guillermo Díaz-Sainz would like to thank the Academic Planning and Teaching Staff Vice-chancellorship of University de Cantabria and the Young Chemical Researchers Group, belonging to the Royal Spanish Society of Chemistry (JIQ-RSEQ) for financial help to carry out the research stay at the Faculty of Engineering of the University of Porto in which the present work was developed

Continuous carbon dioxide electroreduction to formate coupled with the single-pass glycerol oxidation to high value-added products

CO2 electroreduction has been considered a promising alternative to simultaneously reduce CO2 emissions and produce value-added products. Among others, the production of formic acid/formate is particularly attractive. Although promising results have already been obtained in the literature, one of the recent approaches to improve the process deals with the use of an alternative reaction at the anode instead of the traditional oxygen evolution reaction (OER). In this context, this work reports, for the first time, the study of the CO2 electroreduction to formate coupled with the electrooxidation of glycerol to high-added value products where both half-reactions operate in a continuous mode with a single pass of the reactants through the electrochemical cell. Interestingly, at the cathode, similar results to those previously reported were obtained, reaching formate concentrations of about 18 g·L-1 at a 200 mA·cm-2. In addition, at the anode, promising dihydroxyacetone productions of 196 µmol·m-2·s-1 were simultaneously achieved in the output stream of the anodic compartment. These findings represent a significant step forward for the development and application of the technology.The authors gratefully acknowledge financial support through projects PID2019–108136RB-C31, PID2019–108136RB-C32 and PID2020–112845RB-I00 (AEI/10.13039/501100011033)

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​

Continuous carbon dioxide electroreduction to formate coupled with the single-pass glycerol oxidation to high value-added products

CO2 electroreduction has been considered a promising alternative to simultaneously reduce CO2 emissions and produce value-added products. Among others, the production of formic acid/formate is particularly attractive. Although promising results have already been obtained in the literature, one of the recent approaches to improve the process deals with the use of an alternative reaction at the anode instead of the traditional oxygen evolution reaction (OER). In this context, this work reports, for the first time, the study of the CO2 electroreduction to formate coupled with the electrooxidation of glycerol to high-added value products where both half-reactions operate in a continuous mode with a single pass of the reactants through the electrochemical cell. Interestingly, at the cathode, similar results to those previously reported were obtained, reaching formate concentrations of about 18 g·L-1 at a 200 mA·cm-2. In addition, at the anode, promising dihydroxyacetone productions of 196 µmol·m-2·s-1 were simultaneously achieved in the output stream of the anodic compartment. These findings represent a significant step forward for the development and application of the technology.The authors gratefully acknowledge financial support through projects PID2019–108136RB-C31, PID2019–108136RB-C32 and PID2020–112845RB-I00 (AEI/10.13039/501100011033)

Evaluation of nickel anodes in the continuous electroreduction process of carbon dioxide to formate in a filter press reactor

Máster en Ingeniería Químic

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​