Explore the vast range of titles available.

Perovskite oxides have emerged as alternative anode materials for hydrocarbon‐fueled solid oxide fuel cells (SOFCs). Nevertheless, the sluggish kinetics for hydrocarbon conversion hinder their commercial applications. Herein, a novel dual‐exsolved self‐assembled anode for CH4‐fueled SOFCs is developed. The designed Ru@Ru‐Sr2Fe1.5Mo0.5O6‐δ(SFM)/Ru‐Gd0.1Ce0.9O2‐δ(GDC) anode exhibits a unique hierarchical structure of nano‐heterointerfaces exsolved on submicron skeletons. As a result, the Ru@Ru‐SFM/Ru‐GDC anode‐based single cell achieves high peak power densities of 1.03 and 0.63 W cm−2 at 800 °C under humidified H2 and CH4, surpassing most reported perovskite‐based anodes. Moreover, this anode demonstrates negligible degradation over 200 h in humidified CH4, indicating high resistance to carbon deposition. Density functional theory calculations reveal that the created metal‐oxide heterointerfaces of Ru@Ru‐SFM and Ru@Ru‐GDC have higher intrinsic activities for CH4 conversion compared to pristine SFM. These findings highlight a viable design of the dual‐exsolved self‐assembled anode for efficient and robust hydrocarbon‐fueled SOFCs. To achieve efficient and robust CH4 fueled solid oxide fuel cells, a hierarchical Ru@Ru‐Sr2Fe1.5Mo0.5O6‐δ (SFM)/Ru‐Gd0.1Ce0.9O2‐δ (GDC) anode is developed by an innovative integration of self‐assembly and dual exsolution. The single cell using this anode delivers a high peak power density of 0.63 W cm−2 at 800 °C and a remarkable stability for 200 h using humidified CH4 as fuel.

Although conglomerates composed of clasts and matrix are commonly interbedded with sandstones at geologic CO2 storage sites, their residual trapping behavior remains poorly understood. This study investigates the influence of clast‐induced heterogeneity on residual CO2 trapping during water imbibition, using two natural conglomerate cores from the Janggi Basin, Republic of Korea. Petrophysical characterization revealed wide permeability variations and distinct spatial variations of clasts across the two cores, which were incorporated into core‐scale multiphase flow simulations. Results show that clasts not only act as flow barriers but also govern the internal pressure field, leading to localized CO2 exsolution and heterogeneous trapping behaviors. Pressure gradients across clasts triggered phase transitions from dissolved to supercritical phase CO2, which accumulated and became immobilized within narrow matrix pathways and clast interiors that are typically inaccessible to supercritical phase CO2. Additionally, clast‐induced preferential water flow stabilized residually trapped CO2 by limiting dissolution and mobilization, thereby expanding the spatial domain of residual trapping and enhancing its efficiency. Despite pronounced heterogeneity, the residual trapping efficiencies observed (34%–78%) were comparable to those reported for homogeneous sandstone and carbonate formations. These findings highlight the potential of well‐characterized conglomerates as viable targets for geological CO2 storage.

Nanoparticles In situ SAXS/WAXS tracks nanoparticle formation and evolution in exsolved and infiltrated Ni‐based perovskites. The technique captures nucleation, growth, and coarsening dynamics with high temporal resolution, providing statistically robust insights into structural and morphological transformations. More details can be found in the Research Article by María Balaguer, Cecilia Solís, and co‐workers (DOI: 10.1002/admi.202500776).

Exsolution is a promising method to design metal nanoparticles for electrocatalysis and renewable energy. Metal nanoparticles exsolved from perovskite oxide lattices have been utilized as catalysts in many energy fields because of their high durability and excellent electro-catalytic properties. Although this method has received much attention in recent years, a comprehensive understanding is still lacking because of difficulties in finding a rational combination of driving forces and perovskite supports. Thus, the aim of our work here is to recapitulate the principles of exsolution and collect various exsolution studies by categorizing the driving forces of exsolution and the structural characteristics of perovskite supports. These classifications provide guidelines for selecting suitable materials groups and remodeling existing materials, thereby exploring applications of catalysts using exsolution that are applicable to academic and industrial fields.

Over the last decade, exsolution has emerged as a powerful new method for decorating oxide supports with uniformly dispersed nanoparticles for energy and catalytic applications. Due to their exceptional anchorage, resilience to various degradation mechanisms, as well as numerous ways in which they can be produced, transformed and applied, exsolved nanoparticles have set new standards for nanoparticles in terms of activity, durability and functionality. In conjunction with multifunctional supports such as perovskite oxides, exsolution becomes a powerful platform for the design of advanced energy materials. In the following sections, we review the current status of the exsolution approach, seeking to facilitate transfer of ideas between different fields of application. We also explore future directions of research, particularly noting the multi-scale development required to take the concept forward, from fundamentals through operando studies to pilot scale demonstrations.

Symmetric solid oxide fuel cells (SSOFCs) have gained significant attention owing to their cost-effective fabrication, superior thermomechanical compatibility, and enhanced long-term stability. Ammonia (NH3), an excellent hydrogen carrier, is a promising clean energy source with high energy density, easy transportation and storage. Notably, NH3 contained only nitrogen and hydrogen, making it carbon-free. In this study, we synthesize the highly active symmetric electrode material Pr0.32Sr0.48Fe0.75Ni0.2Ru0.05O3−δ (PSFNRu) by replacing partial Fe in Pr0.32Sr0.48Fe0.8Ni0.2O3−δ (PSFN) with 5 mol% Ru. PSFNRu possesses a sufficient quantity of oxygen vacancies, with the capacity to in-situ exsolved alloy nanoparticles (ANPs) in a reducing atmosphere. This nanocomposite is found to promote electrochemical reactions. For example, at 800 °C, the SSOFC employing the PSFNRu electrode achieves a peak power density (PPD) of 736 mW·cm−2 when using hydrogen (H2) as the fuel. Under NH3 conditions, the cell delivers a PPD of 547 mW·cm−2, significantly surpassing the 462 mW·cm−2 recorded for a comparable cell employing the PSFN electrode. The enhanced cell performance is mainly ascribed to Ru doping, which boosts the ORR activity and facilitates the in-situ exsolution of ANPs at the anode, increasing active sites and accelerating NH3 decomposition. In addition, remarkable operational stability of the single cell (172 h under NH3 fuel at 700 °C) is also demonstrated. These encouraging experimental results highlight the superiority of PSFNRu as the bi-functional electrodes for direct ammonia symmetric solid oxide fuel cells (DA-SSOFCs), and providing a potential and reliable pathway towards accelerating the development of DA-SSOFCs.

Effective electrocatalysts are crucial for facilitating the oxygen evolution reaction (OER), the anodic reaction of water electrolysis for renewable green hydrogen production. Perovskite oxides are a group of potential catalysts featuring the lattice oxygen mechanism (LOM) for OER, where O2 formation commences via a lattice oxygen redox process. The LOM pathway breaks the thermodynamic limitation of the adsorbate evolution mechanism (AEM) and achieves a high intrinsic activity. However, perovskite oxides often suffer high OER overpotentials due to the insufficient activation of the LOM pathway. Typically, the overpotential exceeds 300 mV at 10 mA cm−2. This greatly impedes the practical applications of perovskite oxide based OER catalysts. Here, it is demonstrated that the B‐site‐metal exsolution of a La0.6Sr0.4Fe0.8Ni0.2O3‐δ perovskite increases the activity of LOM by a factor of 3.8 at 400 mV overpotential. The activated LOM pathway leads to a 36‐mV reduction in the overpotential at 10 mA cm−2 (from 310 mV to 274 mV) and a 2× increase in the turnover frequency (TOF) at 450 mV overpotential. A membrane electrode assembly (MEA) water electrolyzer equipped with this LSFN‐based catalyst offers 1 A cm−2 current density at 2.46 V and 24‐h operation stability. B‐site‐metal exsolution of perovskite oxides by H2 treatment at high temperatures increases the O vacancy concentration and enhances oxygen evolution activity via the lattice oxygen mechanism (LOM) pathway. As an example, La0.6Sr0.4Fe0.8Ni0.2O3‐δ (LSFN) with B‐site‐metal exsolution offers a 3.8× increase in LOM activity compared to the pristine LSFN and 1 A cm−2 current density at 2.46 V during 24‐h electrolysis.

HighlightsFundamental mechanisms in terms of driving force, material design, and exsolution processes are outlined, and novel behaviors of socketing and shape-shifting throughout the interaction with the oxide support are discussed.This review examines the key control factors, encompassing external conditions and intrinsic properties that affect the surface exsolution of metallic nanoparticles.The extraordinary nature of exsolution particles and their effect on various applications are discussed, along with the latest strategies for improving exsolution behavior.Supported nanoparticles have attracted considerable attention as a promising catalyst for achieving unique properties in numerous applications, including fuel cells, chemical conversion, and batteries. Nanocatalysts demonstrate high activity by expanding the number of active sites, but they also intensify deactivation issues, such as agglomeration and poisoning, simultaneously. Exsolution for bottom-up synthesis of supported nanoparticles has emerged as a breakthrough technique to overcome limitations associated with conventional nanomaterials. Nanoparticles are uniformly exsolved from perovskite oxide supports and socketed into the oxide support by a one-step reduction process. Their uniformity and stability, resulting from the socketed structure, play a crucial role in the development of novel nanocatalysts. Recently, tremendous research efforts have been dedicated to further controlling exsolution particles. To effectively address exsolution at a more precise level, understanding the underlying mechanism is essential. This review presents a comprehensive overview of the exsolution mechanism, with a focus on its driving force, processes, properties, and synergetic strategies, as well as new pathways for optimizing nanocatalysts in diverse applications.

The excellent dielectric properties and tunable structural design of metal sulfides have attracted considerable interest in realizing electromagnetic wave (EMW) absorption. However, compared with traditional monometallic and bimetallic sulfides that are extensively studied, the unique physical characteristics of solid‐solution‐type sulfides in response to EMW have not been revealed yet. Herein, a unique method for preparing high‐purity solid‐solution‐type sulfides is proposed based on solid‐phase in situ exsolution of different metal ions from hybrid precursors. Utilizing CoAl‐LDH/MIL‐88A composite as a precursor, Fe0.8Co0.2S single‐phase nanoparticles are uniformly in situ formed on an amorphous substrate (denoted as CoAl), forming CoAl/Fe0.8Co0.2S heterostructure. Combing with density functional theory (DFT) calculations and wave absorption simulations, it is revealed that Fe0.8Co0.2S solid solution has stronger intracrystal polarization and electronic conductivity than traditional monometallic and bimetallic sulfides, which lead to higher dielectric properties in EM field. Therefore, CoAl/Fe0.8Co0.2S heterostructure exhibits significantly enhanced EMW absorption ability in the low‐frequency region (2–6 GHz) and can achieve frequency screening by selectively absorbing EMW of specific frequency. This work not only provides a unique method for preparing high‐purity solid‐solution‐type sulfides but also fundamentally reveals the physical essence of their excellent EMW absorption performance. In situ exsolution strategy is developed to construct CoAl/Fe0.8Co0.2S heterostructures, in which solid‐solution‐type sulfides inherit internal crystal polarization and outstanding dielectric loss ability.

The rational modification of perovskite oxides (ABO 3− δ ) is essential to improve the efficiency and stability of oxygen electrolysis. Surface engineering represents a facile approach to modify perovskites for enhanced performance. Through compositional design and in situ exsolution, a Ru-doped (La 0.8 Sr 0.2 ) 0.9 Co 0.1 Fe 0.8 Ru 0.1 O 3− δ (LSCFR) perovskite anchored with CoFe(Ru) alloy particles on the surface was fabricated for oxygen evolution reaction (OER) in this work. Experimental results and calculations indicate that Ru-doping promotes the exsolution of CoFe(Ru) from the perovskite parent. Upon exsolution in the reduced atmosphere for 3 h, the catalyst (LSCFR-3) exhibited superior OER performance with an overpotential of 347 mV and a Tafel slope of 54.65 mV·dec −1 , and showed good stability in contrast to the pristine LSCFR. The exsolution of CoFe(Ru) particles, Ru doping, and the increase of surface oxygen vacancies are responsible for the enhancement of OER performance. The findings obtained in this study highlight the possibility of controlling exsolution and composition of nanoparticles by element doping and prove that in situ exsolution is an effective strategy for designing OER catalysts.