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Lithium–sulfur (Li–S) batteries are regarded as promising candidates for next‐generation energy storage systems. However, the slow kinetics and shuttle effects of polysulfides hinder their practical applications. Designing high‐efficiency catalysts to enhance the kinetics and suppress shuttling is one major task for the building of durable Li–S batteries. Here, a Co/CoSe junction is reported to catalyzepolysulfide conversion efficiently because the junction has metallic electron mobility and field‐enhanced catalytic activity. The mechanistic investigation reveals that the difference in the work functions of Co and CoSe rearranges the charge distribution in the junction and strengthens the interaction between polysulfides and CoSe, thereby yielding high catalytic activity. In addition, the relative stability of CoSe, as compared to Co, renders the junction durable upon cycling; therefore, demonstrating long‐term catalytic activity. Such a junction makes full use of metal‐like conductivity and field‐enhanced catalysis and provides an alternative approach to enhancing the catalytic conversion of polysulfides. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Recent progress in colloidal synthesis has realized the preparations of uniform nanocrystal (NC) model catalysts with rich and well‐controlled morphologies that were employed to explore structure‐activity relationships of powder catalysts, similar to single‐crystal‐based model catalysts under ultrahigh vacuum conditions but can work at the same conditions as powder catalysts without the "materials gap" and "pressure gap". In this perspective, the CeO2‐based NC model catalysts with various morphologies are included and their relevant progresses are critically reviewed. The detailed descriptions of morphology‐controlled synthesis and characterizations of uniform CeO2 NCs, and morphology‐dependent catalysis of CeO2‐based NC model catalysts containing pure CeO2 NCs, CeO2‐supported oxide catalysts, and CeO2‐supported metal catalysts, provide us a comprehensive cognition in CeO2‐involved catalytic reactions and also open up a new approach for the fundamental studies of complex heterogeneous catalysis. Finally, a concept of oxide‐based NC model catalysts and outlook of oxide NCs acting not only as model catalysts for the fundamental study but also as the support in tailoring structures and optimizing performance of oxide‐involved catalysts are discussed. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) have attracted significant attention as porous catalyst platforms due to the synthetic modularity of these materials and the diversity of lattice‐confined catalytic active sites that are readily embedded within periodic crystalline frameworks. MOFs offer platforms to heterogenize molecular catalysts, stabilize novel coordination motifs, and leverage confinement effects in catalysis. Crystallinity allows diffraction‐based methods to be employed in the characterization of these catalysts. Access to crystalline MOFs typically requires reversible construction of the metal−ligand (M−L) bonds that connect the SBUs, which provides a mechanism to anneal defects during crystallization. While the required M−L bond reversibility is often promoted by synthesis at elevated temperature, access to crystalline materials based on either transition metals with characteristic slow exchange kinetics or highly basic donor ligands remains a synthetic challenge. Here, we highlight synthetic strategies that leverage M−L exchange kinetics to access MOFs based on kinetically inert ions and extensions of these strategies to the assembly of atomically precise multimetallic materials. [ABSTRACT FROM AUTHOR]

The article presents research into the catalytic effect of iron oxide-rich soil on the process of reducing hexavalent chromium (Cr(VI)) by citric acid. The results of the research are discussed, noting that the catalytic function of the soil surfaces was most effective at low hydrogen-ion concentrations (pH). The inhibition of the soil surface-catalyzed redox reaction at higher pH is mentioned. The reaction's ability to be accelerated with the Fe(II)-Fe(III) redox couple and in the presence of Fe(II) and Fe(III) ions is discussed. Also mentioned is the applicability of the research to advancing processes involving the remediation of soils contaminated with Cr(VI) with natural organic materials.