Direct urea fuel cells: Challenges and opportunities

Sayed, Enas Taha; Eisa, Tasnim; Mohamed, Hend Omar; Abdelkareem, Mohammad Ali; Allagui, Anis; Alawadhi, Hussain

doi:10.1016/j.jpowsour.2018.12.024

Cited by 267 publications

(138 citation statements)

References 200 publications

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“…Urea is a substance found in domestic wastewater, as it is the main component of human and animal urine, containing about 2-2.5 wt% of urea [2,3], and in industrial effluents, such as a large amount of urea-rich wastewater generated by the process of urea synthesis as agricultural fertilizer and animal feed additive [4,5]. When these effluents are discharged into rivers without treatment, they can generate serious environmental contamination and human health problems because urea, despite being non-toxic, can naturally decompose into toxic ammonia and others nitrogenous pollutants [1,[6][7][8]. The treatment of wastewater through traditional methods, such as aeration tanks, presents itself as a great consumer of energy [9].…”

Section: Introductionmentioning

confidence: 99%

“…The treatment of wastewater through traditional methods, such as aeration tanks, presents itself as a great consumer of energy [9]. Urea is conventionally treated by nitrification and denitrification, which are sophisticated and high energy consuming biological processes, generating an excessive cost [7]. As an alternative, urea electro-oxidation has proven to be an effective way for its degradation.…”

Section: Introductionmentioning

confidence: 99%

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Nickel nanoparticles supported by commercial carbon paper as a catalyst for urea electro-oxidation

Coelho

Barbosa

Liu

et al. 2020

Mater Renew Sustain Energy

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Nickel nanoparticles supported by commercial carbon paper (CP) are prepared by pulsed laser deposition with deposition time of 3, 6, and 12 min as a catalyst for urea electro-oxidation. The surface conditions and the morphologies of the prepared electrodes have been characterized by Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. Urea electro-oxidation reaction in KOH solution on the Ni/CP electrodes is investigated by cyclic voltammetry and chronoamperometry. The results show that the electrode with less Ni nanoparticle agglomeration shows higher peak current density, which was achieved in the 3 min deposition samples when normalized by electroactive surface areas. However, the highest current normalized by the area of the carbon paper was achieved in the 6 min deposition sample due to the larger quantity of Ni nanoparticles. All the samples show good stability. Our results suggest that the low density, low cost, and environmental friendly CP can be used as support for Ni nanoparticle as a catalyst for urea electro-oxidation. It thus has great potential for many applications involving urea oxidation, such as wastewater treatments.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nickel nanoparticles supported by commercial carbon paper as a catalyst for urea electro-oxidation

Coelho

Barbosa

Liu

et al. 2020

Mater Renew Sustain Energy

View full text Add to dashboard Cite

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“…Due to the environmental impact of fossil fuels that currently act as our main energy source [1], there is a rapid growth in the usage of renewable energy as an alternative energy source [2][3][4]. Thanks to the reduction in the cost of renewable energies such as biomass [5][6][7], solar thermal [8], and solar PV (photovoltaic) energies [9], wind energy [10], their application is becoming more widespread. Among different renewable energies, the PV system is a promising energy source for sustainable progress [11].…”

Section: Introductionmentioning

confidence: 99%

Stochastic Fractal Search Optimization Algorithm Based Global MPPT for Triple-Junction Photovoltaic Solar System

Rezk

Fathy

2020

Energies

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A significant growth in PV (photovoltaic) system installations have been observed during the last decade. The PV array has a nonlinear output characteristic because of weather intermittency. Partial shading is an environmental phenomenon that causes multiple peaks in the power curve and has a negative effect on the efficiency of the conventional maximum power point tracking (MPPT) methods. This tends to have a substantial effect on the overall performance of the PV system. Therefore, to enhance the performance of the PV system under shading conditions, the global MPPT technique is mandatory to force the PV system to operate close to the global maximum. In this paper, for the first time, a stochastic fractal search (SFS) optimization algorithm is applied to solve the dilemma of tracking the global power of PV system based triple-junction solar cells under shading conditions. SFS has been nominated because it can converge to the best solution at a fast rate. Moreover, balance between exploration and exploitation phases is one of its main advantages. Therefore, the SFS algorithm has been selected to extract the global maximum power point (MPP) under partial shading conditions. To prove the superiority of the proposed global MPPT–SFS based tracker, several shading scenarios have been considered. The idea of changing the shading scenario is to change the position of the global MPP. The obtained results are compared with common optimizers: Antlion Optimizer (ALO), Cuckoo Search (CS), Flower Pollination Algorithm (FPA), Firefly-Algorithm (FA), Invasive-Weed-Optimization (IWO), JAYA and Gravitational Search Algorithm (GSA). The results of comparison confirmed the effectiveness and robustness of the proposed global MPPT–SFS based tracker over ALO, CS, FPA, FA, IWO, JAYA, and GSA.

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“…Electrochemical urea oxidation reaction (UOR) is of great importance in a range of energy-related applications and devices. [1][2][3][4][5] Due to a more negative equilibrium potential (E 0 = 0.37 V vs reversible hydrogen electrode, RHE), UOR is an ideal alternative anode half reaction to conventional oxygen evolution reaction (OER, E 0 = 1.23 V vs RHE) for pure hydrogen and hydrogen peroxide production in energy-saving water electrolyzers. 6,7 Practically, compared to precious pure water oxidation and poisoning methanol/hydrazine oxidation reactions, UOR process has signi cant advantages because urea is globally abundant in human urine, urea-rich wastewater and byproduct of industrial activities.…”

Section: Introductionmentioning

confidence: 99%

Nickel Ferrocyanide as High-Performance Next Generation Electrocatalyst for Urea Oxidation

Geng¹,

Zheng²,

Li³

et al. 2020

Preprint

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Urea oxidation, a key process in energy and environmental science, faces challenges because of the insufficient understanding of its mechanism and the lack of efficient catalysts. Here we demonstrate that nickel ferrocyanide (Ni2Fe(CN)6) molecular catalyst supported on Ni form can drive urea oxidation reaction (UOR) with the record electrochemical activity and stability among all supported catalysts reported so far. A combination of kinetics data, in-situ spectroscopic measurements and energy computations suggests a new UOR pathway that delivers such outstanding performance. Different from most studied Ni-based catalysts with NiOOH derivative as a real catalytically active site for UOR, Ni2Fe(CN)6 appears to be a next-generation catalyst able to directly facilitate a two-step reaction pathway involving a critical reaction of intermediate ammonia’s production (on Ni site) and oxidation (on Fe site). Due to the alternative rate-determining step with a more favorable thermal energetics, Ni2Fe(CN)6 broke the limiting activity of the reported so far UOR catalysts. As a result, the UOR process on Ni2Fe(CN)6 can replace conventional water oxidation process in various energy-saving systems for hydrogen and hydrogen peroxide production.

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Direct urea fuel cells: Challenges and opportunities

Cited by 267 publications

References 200 publications

Nickel nanoparticles supported by commercial carbon paper as a catalyst for urea electro-oxidation

Nickel nanoparticles supported by commercial carbon paper as a catalyst for urea electro-oxidation

Stochastic Fractal Search Optimization Algorithm Based Global MPPT for Triple-Junction Photovoltaic Solar System

Nickel Ferrocyanide as High-Performance Next Generation Electrocatalyst for Urea Oxidation

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