Parasitic structure defect blights sustainability of cobalt-free single crystalline cathodes.

Recent efforts to reduce battery costs and enhance sustainability have focused on eliminating Cobalt (Co) from cathode materials. While Co-free designs have shown notable success in polycrystalline cathodes, their impact on single crystalline (SC) cathodes remains less understood due to the significantly extended lithium diffusion pathways and the higher-temperature synthesis involved. Here, we reveal that removing Co from SC cathodes is structurally and electrochemically unfavorable, exhibiting unusual voltage fade behavior.

Structural, Electrochemical, and (De)lithiation Mechanism Investigation of Cation-Disordered Rocksalt and Spinel Hybrid Nanomaterials in Lithium-Ion Batteries.

Significant demand for lithium-ion batteries necessitates alternatives to Co- and Ni-based cathode materials. Cation-disordered materials using earth-abundant elements are being explored as promising candidates. In this paper, we demonstrate a coprecipitation synthetic approach that allows direct preparation of disordered rocksalt LiFeTiO (r-LFTO·C) and spinel structured hybrid LiFeTiO·C (s-LFTO·C) nanoparticles with a conformal conductive carbon coating.

Unrecoverable lattice rotation governs structural degradation of single-crystalline cathodes.

Transitioning from polycrystalline to single-crystalline nickel-rich cathodes has garnered considerable attention in both academia and industry, driven by advantages of high tap density and enhanced mechanical properties. However, cathodes with high nickel content (>70%) suffer from substantial capacity degradation, which poses a challenge to their commercial viability. Leveraging multiscale spatial resolution diffraction and imaging techniques, we observe that lattice rotations occur universally in single-crystalline cathodes and play a pivotal role in the structure degradation.

Revealing the Nature of Binary-Phase on Structural Stability of Sodium Layered Oxide Cathodes.

The emergence of layered sodium transition metal oxides featuring a multiphase structure presents a promising approach for cathode materials in sodium-ion batteries, showcasing notably improved energy storage capacity. However, the advancement of cathodes with multiphase structures faces obstacles due to the limited understanding of the integrated structural effects. Herein, the integrated structural effects by an in-depth structure-chemistry analysis in the developed layered cathode system NaCuCoNiMnTiO with purposely designed P2/O3 phase integration, are comprehended.

Elucidating Local Structure and Positional Effect of Dopants in Colloidal Transition Metal Dichalcogenide Nanosheets for Catalytic Hydrogenolysis.

Tailoring nanoscale catalysts to targeted applications is a vital component in reducing the carbon footprint of industrial processes; however, understanding and controlling the nanostructure influence on catalysts is challenging. Molybdenum disulfide (MoS), a transition metal dichalcogenide (TMD) material, is a popular example of a nonplatinum-group-metal catalyst with tunable nanoscale properties. Doping with transition metal atoms, such as cobalt, is one method of enhancing its catalytic properties.

Pd-CeO catalyst facilely derived from one-pot generated Pd@Ce-BTC for low temperature CO oxidation.

Due to the capacity to offer abundant catalytic sites within porous solids featuring high surface areas, metal-organic frameworks (MOFs) and their derivatives have garnered considerable attention as prospective catalysts in environmental catalysis. To promote the industrial application of MOFs, there is an urgent need for an effective and environmental-friendly preparation approach. Breaking through the limitation of the traditional two-step preparation method that Pd was introduced to the already prepared Ce-BTC (Pd/Ce-BTC, BTC = 1, 3, 5 benzenetricarboxylate), in this work, we present a novel one-pot solvothermal method for synthesizing the Pd material supported by Ce-BTC (Pd@Ce-BTC).

In Situ Insights into Cathode Calcination for Predictive Synthesis: Kinetic Crystallization of LiNiO from Hydroxides.

Calcination is a solid-state synthesis process widely deployed in battery cathode manufacturing. However, its inherent complexity associated with elusive intermediates hinders the predictive synthesis of high-performance cathode materials. Here, correlative in situ X-ray absorption/scattering spectroscopy is used to investigate the calcination of nickel-based cathodes, focusing specifically on the archetypal LiNiO from Ni(OH).

Cobalt-free composite-structured cathodes with lithium-stoichiometry control for sustainable lithium-ion batteries.

Lithium-ion batteries play a crucial role in decarbonizing transportation and power grids, but their reliance on high-cost, earth-scarce cobalt in the commonly employed high-energy layered Li(NiMnCo)O cathodes raises supply-chain and sustainability concerns. Despite numerous attempts to address this challenge, eliminating Co from Li(NiMnCo)O remains elusive, as doing so detrimentally affects its layering and cycling stability. Here, we report on the rational stoichiometry control in synthesizing Li-deficient composite-structured LiNiMnO, comprising intergrown layered and rocksalt phases, which outperforms traditional layered counterparts.

Fine-Tuning of Pt Dispersion on AlO and Understanding the Nature of Active Pt Sites for Efficient CO and NH Oxidation Reactions.

Fine-tuning the dispersion of active metal species on widely used supports is a research hotspot in the catalysis community, which is vital for achieving a balance between the atomic utilization efficiency and the intrinsic activity of active sites. In this work, using bayerite Al(OH) as support directly or after precalcination at 200 or 550 °C, Pt/AlO catalysts with distinct Pt dispersions from single atoms to clusters (. 2 nm) were prepared and evaluated for CO and NH removal.

Hydroxyls on CeO Support Promoting CuO/CeO Catalyst for Efficient CO Oxidation and NO Reduction by CO.

Transition metal catalysts, such as copper oxide, are more attractive alternatives to noble metal catalysts for emission control due to their higher abundance, lower cost, and excellent catalytic activity. In this study, we report the preparation and application of a novel CuO/CeO catalyst using a hydroxyl-rich Ce(OH) support for CO oxidation and NO reduction by CO. Compared to the catalyst prepared from a regular CeO support, the new CuO/CeO catalyst prepared from the OH-rich Ce(OH) (CuO/CeO-OH) showed significantly higher catalytic activity under different testing conditions.

Migration and aggregation of Pt atoms on metal oxide-supported ceria nanodomes control reverse water gas shift reaction activity.

Single-atom catalysts (SACs) are particularly sensitive to external conditions, complicating the identification of catalytically active species and active sites under in situ or operando conditions. We developed a methodology for tracing the structural evolution of SACs to nanoparticles, identifying the active species and their link to the catalytic activity for the reverse water gas shift (RWGS) reaction. The new method is illustrated by studying structure-activity relationships in two materials containing Pt SACs on ceria nanodomes, supported on either ceria or titania.

Tuning the Interaction between Platinum Single Atoms and Ceria by Zirconia Doping for Efficient Catalytic Ammonia Oxidation.

Aiming at the development of an efficient NH oxidation catalyst to eliminate the harmful NH slip from the stationary flue gas denitrification system and diesel exhaust aftertreatment system, a facile ZrO doping strategy was proposed to construct Pt/CeZrO catalysts with a tunable Pt-CeO interaction strength and Pt-O-Ce coordination environment. According to the results of systematic characterizations, Pt species supported on CeZrO were mainly in the form of single atoms when ≥ 0.7, and the strength of the Pt-CeO interaction and the coordination number of Pt-O-Ce bond (CN) on Pt/CeZrO showed a volcanic change as a function of the ZrO doping amount.

Structure-Property Relationships for Nickel Aluminate Catalysts in Polyethylene Hydrogenolysis with Low Methane Selectivity.

Earth-abundant metals have recently been demonstrated as cheap catalyst alternatives to scarce noble metals for polyethylene hydrogenolysis. However, high methane selectivities hinder industrial feasibility. Herein, we demonstrate that low-temperature ex-situ reduction (350 °C) of coprecipitated nickel aluminate catalysts yields a methane selectivity of <5% at moderate polymer deconstruction (25-45%).

Surface Lattice-Embedded Pt Single-Atom Catalyst on Ceria-Zirconia with Superior Catalytic Performance for Propane Oxidation.

Tuning the metal-support interaction and coordination environment of single-atom catalysts can help achieve satisfactory catalytic performance for targeted reactions. Herein, via the facile control of calcination temperatures for Pt catalysts on pre-stabilized CeZrO (CZO) support, Pt single atoms (Pt) with different strengths of Pt-CeO interaction and coordination environment were successfully constructed. With the increase in calcination temperature from 350 to 750 °C, a stronger Pt-CeO interaction and higher Pt-O-Ce coordination number were achieved due to the reaction between PtO and surface Ce species as well as the migration of Pt into the surface lattice of CZO.

Simultaneous Elucidation of Solid and Solution Manganese Environments via Multiphase Extended X-ray Absorption Fine Structure Spectroscopy in Aqueous Zn/MnO Batteries.

Aqueous Zn/MnO batteries (AZMOB) with mildly acidic electrolytes hold promise as potential green grid-level energy storage solutions for clean power generation. Mechanistic understanding is critical to advance capacity retention needed by the application but is complex due to the evolution of the cathode solid phases and the presence of dissolved manganese in the electrolyte due to a dissolution-deposition redox process. This work introduces multiphase extended X-ray absorption fine structure (EXAFS) analysis enabling simultaneous characterization of both aqueous and solid phases involved in the Mn redox reactions.

Fine-tuned local coordination environment of Pt single atoms on ceria controls catalytic reactivity.

Constructing single atom catalysts with fine-tuned coordination environments can be a promising strategy to achieve satisfactory catalytic performance. Herein, via a simple calcination temperature-control strategy, CeO supported Pt single atom catalysts with precisely controlled coordination environments are successfully fabricated. The joint experimental and theoretical analysis reveals that the Pt single atoms on Pt/CeO prepared at 550 °C (Pt/CeO-550) are mainly located at the edge sites of CeO with a Pt-O coordination number of ca.

Pt Atomic Single-Layer Catalyst Embedded in Defect-Enriched Ceria for Efficient CO Oxidation.

The local coordination structure of metal sites essentially determines the performance of supported metal catalysts. Using a surface defect enrichment strategy, we successfully fabricated Pt atomic single-layer (Pt) structures with 100% metal dispersion and precisely controlled local coordination environment (embedded adsorbed) derived from Pt single-atoms (Pt) on ceria-alumina supports. The local coordination environment of Pt not only governs its catalytic activity but also determines the Pt structure evolution upon reduction activation.

Compositionally complex doping for zero-strain zero-cobalt layered cathodes.

The high volatility of the price of cobalt and the geopolitical limitations of cobalt mining have made the elimination of Co a pressing need for the automotive industry. Owing to their high energy density and low-cost advantages, high-Ni and low-Co or Co-free (zero-Co) layered cathodes have become the most promising cathodes for next-generation lithium-ion batteries. However, current high-Ni cathode materials, without exception, suffer severely from their intrinsic thermal and chemo-mechanical instabilities and insufficient cycle life.

Iridate LiIrO: An Antiferromagnetic Insulator.

A polycrystalline iridate LiIrO material was prepared via heating LiO and IrO starting materials in a sealed quartz tube at 650 °C for 48 h. The structure was determined from Rietveld refinement of room-temperature powder neutron diffraction data. LiIrO adopts the nonpolar space group 3̅ with Li atoms occupying the tetrahedral and octahedral sites, which is supported by the electron diffraction and solid-state Li NMR.

Transformation of Highly Stable Pt Single Sites on Defect Engineered Ceria into Robust Pt Clusters for Vehicle Emission Control.

Engineering surface defects on metal oxide supports could help promote the dispersion of active sites and catalytic performance of supported catalysts. Herein, a strategy of ZrO doping was proposed to create rich surface defects on CeO (CZO) and, with these defects, to improve Pt dispersion and enhance its affinity as single sites to the CZO support (Pt/CZO). The strongly anchored Pt single sites on CZO support were initially not efficient for catalytic oxidation of CO/CH.