Strategic interstitial Mn doping in Mg 3 (Bi, Sb) 2 single crystal simultaneously achieves high thermoelectric performance and intrinsic chemical stability, enabling robust module operation for over 300 hours in ambient air.

Li-rich disordered rock-salt oxides have been extensively studied as electrode materials for lithium-ion batteries, however, their diffusion of lithium ions relies on the presence of excess lithium-ion content (>54.5 atom% relative to total metal ions). An emerging high-entropy strategy can reduce the lithium-ion content and enhance lithium-ion conductivity in sodium superionic conductor (e.g. Li(Ti,Zr,Sn,Hf)(2)(PO4)(3)). However, the high ionic conductivity in Li-stuffed disordered rock-salt oxides with low lithium-ion content is generally attributed to its cocktail effect, and the underlying mechanisms remains unclear. Here, we develop a robust Li-poor disordered rock-salt high-entropy oxide, (MgCoNiCuZn)(0.75)Li0.25O (HEOLi) as an artificial solid electrolyte interphase coating layer to stabilize lithium metal anodes, achieving an impressive cycling stability of over 15000 h. We elucidate a cocktail effect of HEOLi arising from its disordered structure of HEOLi, with unique crystallographic local structural distortions, delocalized electron structure, and energy gradients, enabling high Li-ion conductivity. These energy gradients reduce the overall energy barrier and promote Li+ hopping through preferential pathways within the HEOLi. This work offers insight into the cocktail effect of high-entropy and the Li-ion conduction mechanism, facilitating the rational design of conductive high-entropy ceramics.

Herein, a sustainable route to novel aromatic monomer, dimethyl 1,2,3,4-tetrahydro-1,4-methanonaphthalene5,8-dicarboxylate, was developed, in which dimethyl muconate and norbornene used as the diene and dienophile undergo Diels-Alder reaction followed by dehydrogenation. The polycyclic cycloadduct, octahydro-1,4methanonaphthalene-5,8-dicarboxylate, could be synthesized without catalyst. The activated carbon modified with sulfuric acid generated more oxygen-containing groups, stronger acidity and more acidic sites. Highly dispersed palladium metal particles with an average particle size of about 1.0 nm exhibited excellent activity in the dehydrogenation reaction and the yield of target product reached 73.8 %.

Protonic ceramic electrochemical cells (PCECs) have potential as long-duration energy storage systems. However, their operational stability is limited under industrially relevant conditions due to the intrinsic chemical instability of doped barium cerate-based electrolytes and oxygen electrodes against H2O, as well as the poor electrode-electrolyte interfacial contact. Here we present a conformally coated scaffold (CCS) design to comprehensively address these issues. A porous proton-conducting scaffold is constructed and conformally coated with Pr1.8Ba0.2NiO4.1 electrocatalyst, which has high chemical stability against H2O, triple conductivity and hydration capability, and protects vulnerable electrolytes from H2O. The CCS structure consolidates the electrode-electrolyte interfacial bonding to enable fast proton transfer in the percolated network. This design enables PCECs to reach electrolysis stability for 5,000 h at -1.5 A cm-2 and 600 degrees C in 40% H2O. This work provides a general strategy to stabilize PCECs and offers guidance for designing resilient and stable solid-state energy storage systems.

The axial stretching or compression of the twodimensional (2D) plane has been predicted to modulate the properties of 2D materials, such as band structure, electronic transport, and energy conversion. Here, the uniaxial stretching that caused graphdiyne (GDY) 2D plane deformation has been utilized as a handle for constructing an adjustable solid Mgmoisture battery. By extruding the GDY nanosheet array sponge, the transmission of stress along the compressible sponge enables effective and precise in-plane uniaxial stretching of the GDY 2D layers, resulting in changes in the electronic structure, thereby enhancing its catalytic activity. Both experiments and density functional theory calculations reveal the narrowed band structure (from 0.47 to 0.30 eV) and boosted hydrogen evolution performance of the GDY-based electrode under uniaxial stretching and then enhancing the output of the battery. The maximum power density increases from 0.40 to 7.0 mW cm-2 by 17.5 times. This energy device with external physical field regulation based on axial stretching of the 2D plane provides a new approach for the development and integration of adjustable smart electronic devices and batteries.

Solar thermochemical hydrogen (STCH) production using non-stoichiometric redox oxides for two-step watersplitting in a chemical looping way is a promising technology for sustainable solar H2 production. Perovskite oxides have attracted significant interest due to their favorable thermodynamic properties. However, their H2 production, cycling and phase stability, and scalability are still limited due to a limited compositional space in traditional perovskite oxides. Specifically, costly rare earth and critical transition metal elements are generally used, restricting their economic viability for large-scale applications. Expanding from the emerging field of highentropy ceramics, this work explores a new family of compositionally complex perovskite oxides (CCPOs), Sr (Ti(1-x)/3Mn(1-x)/3Fe(1-x)/3Crx)O3, with tunable Cr content (x) from 0 to 0.25 for STCH production. Notably, this class of CCPOs eliminates the use of expensive rare earth and critical transition metals for STCH applications. This study shows that increasing the Cr content to 0.2 enhances the hydrogen production of Sr (Ti0.2667Mn0.2667Fe0.2667Cr0.2)O3 to 380 mu mol/g in a short 1-h two-step redox duration, surpassing Sr (Ti0.333Mn0.333Fe0.333)O3 with a hydrogen production of 228 mu mol/g. Additionally, entropy stabilization may contribute to the phase stability during thermochemical redox cycling, enabling a relatively stable H2 production of Sr(Ti0.2667Mn0.2667Fe0.2667Cr0.2)O3 over 21 cycles. This study provides a new class of CCPOs composed of relatively low-cost alkaline earth and transition metals with great potential for STCH and other chemical looping applications.

Hydrogels have attracted widespread attention in the field of surface radioactivity decontamination due to their mild and rapid decontamination processes, as well as their tunable properties. However, fabricating decontamination hydrogels with suitable mechanical properties and environmental adaptability remains challenging. In this study, a tough and freeze-resistant hydrogel (PEAG) was prepared based on graphene oxide (GO), polyvinyl alcohol (PVA), agar (AG), and ethylene glycol (EG) for efficient removal of surface radioactive uranium (VI). Due to the dynamic action of borax and the formation of a nanocomposite dual-network structure, PEAG possesses improved modulus and excellent self-healing properties, allowing the hydrogel to be easily applied to surfaces and to perform operations such as stretching and peeling. In addition, it is found that the PEAG achieves excellent decontamination rates for radioactive uranium (VI) on glass (88.53+1.43 %), stainless steel (86.72 +3.41 %), rubber (67.0+2.43 %), ceramics (82.39+1.78 %), and cement (64.52+1.72 %) surfaces, respectively. XPS and contact angle experiments demonstrated that the improved decontamination performance of PEAG is mainly due to the abundant hydroxyl and carbonyl functional groups in the graphene oxide adsorbent, which provide a rich source of complexation sites and enhance its hydrophilic properties for PEAG. Additionally, due to the incorporation of EG, the PEAG hydrogel exhibits good environmental adaptability, which can retain internal moisture and maintain softness and decontamination stability at low temperatures of-20 degrees C. Therefore, PEAG hydrogel is a promising and sustainable candidate material for various surface radioactive decontamination scenarios.

Strippable hydrogels are recognized as promising candidates for radioactive decontamination applications owing to their non-generation of liquid waste, negligible substrate damage potential, and scalable deployment characteristics. Nevertheless, limitations persist in conventional hydrogel systems regarding the retrieval of desiccated film residues. In this study, a starch/Fe3O4 composite hydrogel was developed through a one-pot polymerization methodology that capitalizes on the inherent non-toxicity of starch constituents and the magnetophoretic properties of Fe3O4 nanoparticles. The synthesized hydrogel demonstrated pronounced embrittlement characteristics upon dehydration, attaining a saturation magnetization value of 2.98 emu/g (at 4 % Fe3O4 loading), which facilitated magnetic recovery operations with retrieval efficiencies exceeding 96.67 %. Uranium decontamination efficiencies were quantified across multiple substrates, yielding values of 89.62 % for ceramic, 81.33 % for glass, 83.93 % for steel, 68.95 % for rubber, 54.64 % for paint, and 11.82 % for concrete. Rheological characterization revealed shear-thinning behavior, with viscosity reduced to 93.21 mPa & sdot;s under shear stress conditions, thereby enabling effective spray deposition. The Application trial demonstrated that starch/F3O4 hydrogel can be successfully applied to the concrete surface by spraying, and brittle fracture can be recycled by magnets. This investigation establishes a sustainable decontamination paradigm through the synergistic integration of magnetically assisted recovery mechanisms with the adsorptive capacity of starch-based matrices, addressing both operational efficacy and post-treatment waste management challenges.

The long-term operation of balance-of-plant (BoP) components in solid oxide fuel cells (SOFCs) relies on the presence of a stable and durable oxide layer. In this study, we investigate the oxidation and chromium (Cr) evaporation behaviors of two developmental alumina-forming austenitic (AFA) alloys compared to chromia-forming alloy 625 at 900 degrees C in air with 10% water vapor. Transpiration tests, weight gain tests, X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, and scanning transmission electron microscopy with energy dispersive X-ray analysis are employed to evaluate the oxidation and Cr evaporation behaviors. Our findings reveal that alloy 625 exhibits significantly higher rates of Cr evaporation compared to OC11 (Y and Hf additions) and OC11LZ (Y and Zr additions), with evaporation amounts -56 and -28 times greater, respectively. The observed differences between OC11 and OC11LZ can be attributed to variations in the formed oxide scales during long-term operation. Furthermore, we examine the influence of Hf and Zr reactive elements on the long-term oxidation and chromium evaporation behaviors, providing insights into the role of these elements in enhancing the performance and stability of the alloys. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

In this work, we have introduced an optimized Debye-Gr & uuml;neisen model that revolutionizes the determination of the Debye temperature and Gr & uuml;neisen parameters. Unlike conventional methods, our model requires only the 0 K energy volume data for a material as input, eliminating the need to determine the bulk modulus and its pressure derivative, which often pose challenges due to numerical uncertainties. This unique feature sets our model apart from existing approaches and streamlines the process, enabling accurate predictions of thermal expansion behavior across various materials. To demonstrate its effectiveness, we showcase its excellent agreement with measured coefficients of thermal expansion (CTE) for the nickel-cobalt-chromium-aluminum-yttrium (Ni-Co-CrAl-Y) bond-coating system. Additionally, we apply our approach by conducting a high-throughput search for potential bond-coating materials among 90,000 compositions within the aluminum-cobalt-chromium-iron-nickel (Al-Co-Cr-Fe-Ni) system. From this extensive search, four compositions are synthesized, and the measured CTE values agree very well with theoretical predictions, hence validating our approach. The current optimized DebyeGr & uuml;neisen model combined with Density Functional Theory (DFT)-based thermodynamic database enables reliable and efficient high-throughput calculations of CTE of of a material without expensive phonon calculations.

The A-site high-entropy perovskite oxide (La1/6Pr1/6Nd1/6Gd1/6Sr1/6Ba1/6)MnO3 with enhanced hydrogen production, phase stability, and surface oxygen exchange kinetics, offering the potential for tailoring properties in the STCH application.

The chromium (Cr) evaporation from balance-of-plant (BoP) component alloys in high-temperature environments can severely deteriorate the electrochemical performance of solid oxide cells (SOCs) in fuel (SOFC) and electrolysis (SOEC) modes. However, accurate assessment of Cr evaporation is challenging due to potential interferences from the experimental conditions and test apparatus. In this study, we investigate four distinct methods for assessing the Cr evaporation rates of candidate alumina-forming austenitic and chromia-forming austenitic BoP alloys under relevant simulated SOC operating conditions of 800–900 °C in air with 10% H 2 O. A method using a sodium carbonate coated thin alumina tube is identified, which effectively mitigates the interference caused by (1) the deposition of silicon deposits originating from quartz furnace tubes, (2) detrimental effects of sodium species on the oxidation process of alloys from the sodium carbonate used to enhance Cr oxy hydroxide species capture, or (3) chemical interaction between Cr gaseous species and the alumina furnace tube. This optimal method provides improved assessment of Cr evaporation, enabling further efforts to build correlation between Cr species quantities to the degradation rates of SOCs.

Proton exchange membrane water electrolysis is a highly promising hydrogen production technique for sustainable energy supply, however, achieving a highly active and durable catalyst for acidic water oxidation still remains a formidable challenge. Herein, we propose a local microenvironment regulation strategy for precisely tuning In−RuO 2 /graphene (In−RuO 2 /G) catalyst with intrinsic electrochemical activity and stability to boost acidic water oxidation. The In−RuO 2 /G displays robust acid oxygen evolution reaction performance with a mass activity of 671 A g cat −1 at 1.5 V, an overpotential of 187 mV at 10 mA cm −2 , and long-lasting stability of 350 h at 100 mA cm −2 , which arises from the asymmetric Ru−O−In local structure interactions. Further, it is unraveled theoretically that the asymmetric Ru−O−In structure breaks the thermodynamic activity limit of the traditional adsorption evolution mechanism which significantly weakens the formation energy barrier of OOH*, thus inducing a new rate-determining step of OH* absorption. Therefore, this strategy showcases the immense potential for constructing high-performance acidic catalysts for water electrolyzers.

Solar thermochemical hydrogen generation (STCH) is a promising approach for eco-friendly H2 production, but conventional STCH redox compounds often suffer from thermodynamic and kinetic limitations with limited tunability. Expanding from the nascent high-entropy ceramics field, this study explores a new class of compositionally complex perovskite oxides (La0.8Sr0.2)(Mn(1-x)/3Fe(1-x)/3CoxAl(1-x)/3)O3 for STCH. In situ X-ray diffraction demonstrates the phase stability during redox cycling and in situ X-ray photoelectron spectroscopy shows preferential redox of Co. The extent of reduction increases, but the intrinsic kinetics decreases, with increased Co content. Consequently, (La0.8Sr0.2)(Mn0.2Fe0.2Co0.4Al0.2)O3-{\delta} achieves an optimal balance between the thermodynamics and kinetics properties. The combination of a moderate enthalpy of reduction, high entropy of reduction, and preferable surface oxygen exchange kinetics enables a maximum H2 yield of 395 +- 11 {\mu}mol g-1 in a short 1-hour redox duration. Entropy stabilization expectedly contributes to the structure stability during redox without phase transformation, which enables an exceptional STCH stability for>50 cycles under harsh interrupted conditions. The underlying redox mechanism is further elucidated by the density functional theory based parallel Monte Carlo computation, which represents a new computation paradigm first established here. This study suggests a new class of non-equimolar compositionally complex ceramics for STCH and chemical looping.

To achieve chromium tolerance and high performance, a new series of high-entropy perovskites (HEPs) are investigated as cathode materials for solid oxide fuel cells (SOFCs). Multiple rare-earth, alkaline-earth, and high-order transition metal elements are used for the A-site of this ABO3 structure. A pure phase is achieved through the designed combination of different elements in seven out of eight candidates. Due to the retaining of alkaline-earth elements Sr and/or Ba, the electrical conductivities of these HEPs are in the order of 100 S/cm at 550-700 °C, a value that can practically eliminate the electronic resistance of the porous cathode. Three out of eight candidates show similar or better performance than the (La0.6Sr0.4)(Co0.2Fe0.8)O3-δ (LSCF) benchmark. It is found that A-site elements can cast a substantial influence on the overall performance even with a change as small as 10% of the total cations. It seems that each element has its individual "phenomenal activity" that can be transferred from one candidate to the other in the general setting of the perovskite structure, leading to the best candidate by using the three most active elements simultaneously at the A-site. Excellent Cr tolerance has been observed on the (La0.2Sr0.2Pr0.2Y0.2Ba0.2)Co0.2Fe0.8O3-δ sample, showing degradation of only 0.25%/kh during a 41 day operation in the presence of Cr, while LSCF increases by 100% within the first day in the same condition. X-ray photoelectron spectroscopy discovers no Sr segregation as LSCF is found in this HEP; rather, the active element Y takes more A-sites on the outermost layer after long-term operation.

Al2O3-forming austenitic (AFA) stainless steels are potential replacements for the existing balance of plant (BoP) components in solid oxide fuel cells (SOFCs). In this study, chromium (Cr) poisoning of anode supported cells (ASCs) coupled with various alloys was analyzed by the distribution of relaxation times (DRT). The performance deterioration of ASCs was mainly attributed to the increased polarization resistances of chemisorption of oxygen on the cathode and the oxygen diffusion and reaction in the cathode. The superior performance of ASC coupled with AFA alloys was due to the formed continuous alumina layer which can vastly decrease the evaporated gaseous Cr species, thus alleviating the Cr poisoning on the cathode region.

An advanced smart sensor network is essential to a combustion system, which favors in situ, locally placed, and low-cost gas sensors. However, most chemical/electrochemical sensors fail to work in a combustion boiler, due to demanding operation temperatures (> 1000 °C). This work, for the first time, reports a well-functioning mixed-potential type CO sensor at 1000–1200 °C using nickel oxide (NiO) as the sensing material on the yttrium-stabilized zirconium (YSZ) oxide electrolyte. The influences of feed flow rate, electrode thickness, and porosity on the sensor behavior were investigated and the developed mixed potential gas sensor delivered notable and fast responses to 1000 ppm CO in 3% O2: 109 mV @1000 °C, 40 mV @1100 °C, and 7 mV @1200 °C. The sensing mechanism was identified different from the common theory based on CO oxidation coupled with oxygen reduction. A new mechanism is attributed to the inverse reactions: CO reduction coupled with oxygen evolution. For the first time, an inversion temperature was found for the CO-NiO reaction. Below the inversion temperature, CO oxidation occurs as commonly presented. Above the inversion temperature, CO is electrochemically reduced over NiO into carbon and oxygen ions, evidenced by electrochemical and compositional characterizations. The results can complement CO sensing mechanisms for mixed potential sensors and further trigger more research efforts to expand the working temperature limit of mixed potential sensors for practical application in combustion control systems. Below the inversion temperature, CO oxidationoccurs. Above the inversion temperature, CO is electrochemically reduced overNiO into carbon and oxygen ions. The results can complement CO sensingmechanisms for mixed potential sensors.

The fundamentals, standardization, innovative strategies, and future direction of low-temperature water electrolysis including alkaline (AWE), proton exchange membrane (PEMWE), and anion exchange membrane (AEMWE) water electrolyses are discussed.

The chromium evaporation and oxidation behaviors of alumina-forming austenitic stain-less steels are systematically investigated at 800 degrees C in air +10% H2O relative to 310S for 5000 h. Cr evaporation rates of 310S are about 35 times higher than AFA alloys after 5000 h. Relatively rapid oxidation is observed on 310S after only one 500 h cycle, followed by a modest degree of mass loss and spallation, while the AFA alloys show high oxidation resistance throughout the entire test. Continuous inner alumina layer formed on AFA al-loys stays compact and stable after 5000 h which greatly reduces the Cr evaporation.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

In this study, we report a high performance and redox-stable symmetrical solid oxide fuel cell (SOFC) based on (Ba0.5Sr0.5) (Mo0.1Fe0.9)O3-delta (BSMF) electrode and La0.8Sr0.2Ga0.8Mg0.2O3-delta (LSGM) electrolyte. BSMF is able to operate both as anode and cathode. Excellent electrocatalytic activity has been achieved on BSMF towards hydrogen oxidation and oxygen reduction. Due to its closely matched lattice parameter to LSGM electrolyte, a unique diffuse interface is formed between BSMF and LSGM. Compared to a clean interface, e.g. BSMF/gadolinium doped ceria interface, this diffuse interface promotes the performance of BSMF electrode 1-1.8 times in 600-800 degrees C. Polarization resistance of the BSMF/LSGM specimen is as low as 0.047 and 0.007 Omega cm(2) in humidified H-2 and in air at 800 degrees C, respectively. On the BSMF/LSGM/BSMF symmetrical cell, a maximum power density of 2.28 W/cm(2) is achieved at 800 degrees C, the highest among with redox-stable ceramic electrodes to the best of our knowledge. Redox stability of this cell is confirmed. The role of anode and cathode is reversed back and forth in different operation modes. No apparent degradation is observed through 4 cycles within a 110 h operation period. These findings demonstrate that (Ba0.5Sr0.5) (Mo0.1Fe0.9)O3-delta coupled with LSGM electrolyte is an excellent choice to build a high performance, redox-stable SOFC.