Progress in green hydrogen production and innovative materials for fuel cells: A pathway towards sustainable energy solutions

International Journal of Hydrogen Energy, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 1, 2024

Language: Английский

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Accurate prediction of oxygen vacancy concentration with disordered A-site cations in high-entropy perovskite oxides

npj Computational Materials, Journal Year: 2023, Volume and Issue: 9(1)

Published: Feb. 28, 2023

Abstract Entropic stabilized ABO 3 perovskite oxides promise many applications, including the two-step solar thermochemical hydrogen (STCH) production. Using binary and quaternary A-site mixed {A}FeO as a model system, we reveal that more cation types, especially above four, are on A-site, cell lattice becomes cubic-like but local Fe–O octahedrons distorted. By comparing four different Density Functional Theory-informed statistical models with experiments, show oxygen vacancy formation energies ( $${E}_{V}^{f}$$ E V f ) distribution interactions must be considered to predict non-stoichiometry δ accurately. For STCH distribution, both average spread, can optimized jointly improve Δ (difference of between conditions) in some production levels. This used range water splitting thermodynamically improved by mixing cations perovskites.

Language: Английский

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High-entropy spinel oxide (Fe0.2Mg0.2Mn0.1Al0.3Cr0.2)3O4 as a highly active and stable redox material for methane driven solar thermochemical water splitting

Applied Catalysis B Environment and Energy, Journal Year: 2023, Volume and Issue: 339, P. 123096 - 123096

Published: July 14, 2023

Language: Английский

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Compositionally complex perovskite oxides: Discovering a new class of solid electrolytes with interface-enabled conductivity improvements

Matter, Journal Year: 2023, Volume and Issue: 6(7), P. 2395 - 2418

Published: June 21, 2023

Compositionally complex ceramics (CCCs), including high-entropy ceramics, offer a vast, unexplored compositional space for materials discovery. Herein, we propose and demonstrate strategies tailoring CCCs via combination of non-equimolar designs control grain boundaries (GBs) microstructures. Using oxide solid electrolytes all-solid-state batteries as an example, have discovered class compositionally perovskite oxides (CCPOs) with improved lithium ionic conductivities beyond the limit conventional doping. For that conductivity can be by >60% in (Li0.375Sr0.4375)(Ta0.375Nb0.375Zr0.125Hf0.125)O3-δ compared (Li0.375Sr0.4375)(Ta0.75Zr0.25)O3-δ (LSTZ) baseline. Furthermore, another >70% quenching, achieving >270% LSTZ. Notably, GB-enabled improvements both promoting growth altering GB structures through processing. In broader perspective, this work suggests new routes discovering energy storage many other applications.

Language: Английский

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Predicting Thermochemical Equilibria with Interacting Defects: Sr1−xCexMnO3−δ

PRX Energy, Journal Year: 2024, Volume and Issue: 3(1)

Published: Feb. 16, 2024

Solar thermochemical hydrogen is one of the few potential routes towards direct fuel production from renewable energy sources, but thermodynamic boundary conditions for efficient and economic conversion are challenging. Success or failure a given oxide working material depends on subtle balance between enthalpy entropy contributions in redox processes. Developing mechanistic understanding behavior materials basis atomistic models first-principles calculations an important part advancing technology. One challenge to quantitatively predict equilibria at high concentrations when redox-active defects start interact with each other, thereby impeding formation additional defects. This problem more general importance applications that rely levels off-stoichiometry doping, including, example, batteries, thermoelectrics, ceramic cells. To account such repulsive defect interactions, we introduce statistical mechanics approach, defining expression free interaction based limited sampling configurations density functional theory supercell calculations. The parameterization this contribution as function concentration temperature allows on-the-fly simulation equilibria. approach consistently incorporates finite effects by including leading temperature-dependent case hand, i.e., ideal gas configurational enthalpies entropies. We demonstrate capability utility simulating water splitting processes Sr1−xCexMnO3−δ alloys. Published American Physical Society 2024

Language: Английский

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An updated review and perspective on efficient hydrogen generation via solar thermal water splitting

Wiley Interdisciplinary Reviews Energy and Environment, Journal Year: 2024, Volume and Issue: 13(4)

Published: July 1, 2024

Abstract Solar thermal water splitting (STWS) produces renewable (or green) hydrogen from using concentrated sunlight. Because STWS utilizes energy the entire solar spectrum to drive reduction–oxidation (redox) reactions that split water, it can achieve high theoretical solar‐to‐hydrogen efficiencies. In a two‐step process, metal oxide serves as redox mediator is first heated with sunlight temperatures ( T >1000°C) reduce and evolve oxygen. second step, reduced material exposed steam reoxidize its original oxidation state produce hydrogen. Various aspects of this process are comprehensively reviewed in work, including reduction chemistries active materials considered date, reactors developed facilitate reactions, effects operating conditions—including recent innovation elevated oxidant pressure—on efficiency. To conclude review, perspective on future optimization provided. This article categorized under: Sustainable Energy > Emerging Technologies Hydrogen Fuel Cells New Fuels

Language: Английский

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Manganese-based A-site high-entropy perovskite oxide for solar thermochemical hydrogen production

Journal of Materials Chemistry A, Journal Year: 2023, Volume and Issue: 12(7), P. 3910 - 3922

Published: Dec. 18, 2023

The A-site high-entropy perovskite oxide (La 1/6 Pr Nd Gd Sr Ba )MnO 3 with enhanced hydrogen production, phase stability, and surface oxygen exchange kinetics, offering the potential for tailoring properties in STCH application.

Language: Английский

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Tailored (La_0.2Pr_0.2Nd_0.2Tb_0.2Dy_0.2)₂Ce₂O₇ as a Highly Active and Stable Nanocatalyst for the Oxygen Evolution Reaction

Small, Journal Year: 2024, Volume and Issue: 20(23)

Published: March 14, 2024

Abstract Designing highly active and robust catalysts for the oxygen evolution reaction is key to improving overall efficiency of water splitting reaction. It has been previously demonstrated that evaporation induced self‐assembly (EISA) can be used synthesize porous high surface area cerate‐based fluorite nanocatalysts, substitution Ce with 50% rare earth (RE) cations significantly improves electrocatalyst activity. Herein, defect structure best performing nanocatalyst in series are further explored, Nd 2 O 7 , a combination neutron diffraction pair distribution function analysis. found 3 + cation CeO lattice introduces higher levels Frenkel defects induces partially reduced RE 1.5 5 x phase vacancy ordering. Significantly, it concentration improved electrocatalytic activity enhanced by increasing compositional complexity (number involved) substitution. The resulting novel compositionally‐complex fluorite– (La 0.2 Pr Tb Dy ) shown display low OER overpotential 210 mV at current density 10 mAcm −2 1M KOH, excellent cycling stability. suggested nanocatalysts expands ability tailor catalyst design.

Language: Английский

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Tuning grain boundary cation segregation with oxygen deficiency and atomic structure in a perovskite compositionally complex oxide thin film

Applied Physics Letters, Journal Year: 2024, Volume and Issue: 124(17)

Published: April 22, 2024

Compositionally complex oxides (CCOs) are an emerging class of materials encompassing high entropy and stabilized oxides. These promising advanced leverage tunable chemical bond structure, lattice distortion, disorder for unprecedented properties. Grain boundary (GB) point defect segregation to GBs relatively understudied in CCOs even though they can govern macroscopic material For example, GB local (dis)order distribution, playing a critical role electrochemical reaction kinetics, charge mass transport solid electrolytes. However, compared with conventional oxides, multi-cation CCO systems expected exhibit more phenomena and, thus, prove difficult tune through design strategies. Here, was studied model perovskite LaFe0.7Ni0.1Co0.1Cu0.05Pd0.05O3−x textured thin film by (sub-)atomic-resolution scanning transmission electron microscopy imaging spectroscopy. It is found that correlated cation reducibility—predicted Ellingham diagram—as Pd Cu segregate rich oxygen vacancies (VO··). Furthermore, highly sensitive the concentration spatial distribution VO·· along plane, as well fluctuations atomic structure elastic strain induced disorder, such dislocations. This work offers perspective controlling cations tuning reducibility deficiency, which guide CCOs.

Language: Английский

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Current Status of Green Hydrogen Production Technology: A Review

Sustainability, Journal Year: 2024, Volume and Issue: 16(20), P. 9070 - 9070

Published: Oct. 19, 2024

As a clean energy source, hydrogen not only helps to reduce the use of fossil fuels but also promotes transformation structure and sustainable development. This paper firstly introduces development status green at home abroad then focuses on several advanced production technologies. Then, advantages shortcomings different technologies are compared. Among them, future source tends be electrolysis water production. Finally, challenges application prospects process technology discussed, is expected become an important part realizing global

Language: Английский

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