Electrochemical reduction of nitrite and CO₂, and oxidation of organic fuels
Notice bibliographique
Résumé
In today's world, the need for sustainable technology is more crucial than ever. With the continuous growth in demand for resources and energy, the environment is under severe strain due to climate change, depletion of natural resources, and environmental degradation. Electrochemical techniques offer a promising solution for sustainable development. One such approach is using carbon dioxide as a renewable, non-fossil-based feedstock to produce fuels and value-added chemicals via electrochemical processes that use renewable energy sources. In addition, coelectrolysis of carbon dioxide with environmental pollutants such as NO₂-, NO₃-, and NO has shown promising results for producing of sustainable fuels, commodity chemicals, and fertilizers while reducing environmental pollutants. Our research focuses on coreduction of CO₂ with nitrite (NO₂-) to produce ammonia and urea simultaneously using renewable power sources. Among the effective catalysts for this process, metallophthalocyanines (M-Pc) have been shown to be successful, especially iron-based phthalocyanine, with a high current efficiency. We investigated the electrochemical coreduction of NO₂- and CO₂ at carbon-supported iron-based phthalocyanine electrocatalysts to produce ammonia and urea under ambient conditions. To understand the electrochemical behavior of the electrodes, we used both cyclic voltammetry and chronoamperometry in 0.1 M NaHCO₃ and 5 mM NaNO₂ solution under N₂ and CO₂ environments. The produced ammonia and urea concentrations were determined using two different spectrophotometric techniques, and secondary analytical techniques, liquid-chromatography-mass spectrometry (LC-MS) and proton nuclear magnetic resonance spectrometric (1H-NMR), were used to confirm the accuracy of the results. Our results indicate that it is possible to produce urea at low overpotentials at various ironbased phthalocyanine electrocatalysts in NaHCO₃ as an electrolyte. However, our experiments revealed that ammonia was the primary electrolysis product when using carbon-supported iron phthalocyanine (FePc/C) as an electrocatalyst. At a potential of -0.347 V vs RHE, 85% of the current was used for NH₃ production, while only 4.1% was utilized for urea production. Nevertheless, we observed a significant amount of urea production at FePc/C, with a maximum yield of 5.8% at the lowest overpotential (-0.047 V vs RHE). We also observed that carbon supported sulfonated iron(III) phthalocyanine (FeTSPc/C) produced the highest faradaic yield (54.8%) of urea at a potential of +0.053 V vs RHE, with 25% coproduction of NH3. In a PEM electrolysis cell, the FePc/C catalyst demonstrated the potential to produce urea and ammonia simultaneously using very low NO₂- concentrations. The faradaic efficiency for urea was increased from 2.8% to 15.9% compared to the normal three-electrode cell. In addition to producing commodity chemicals, research has also focused on developing electrocatalysts for fuel cell applications. PtBi/C and PtPb/C catalysts were prepared by the surface decoration of a commercial Pt/C catalyst, and their catalytic activities for electrochemical oxidation of formic acid, methanol and ethanol were compared. It was found that the currents at 0 V vs SCE for formic acid oxidation at the PtBi/C and PtPb/C catalysts were ~ 6 and ~ 2 times higher, respectively, compared to the unmodified Pt/C catalyst. In addition, the PtBi/C catalyst also showed slightly higher activity for ethanol oxidation at low potentials compared to the unmodified Pt/C.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».