A picolinamide iridium catalyst immobilized on an aluminum-hydride anchor for the selective dehydrogenation of neat formic acid.

The dehydrogenation of formic acid can provide an efficient pathway for hydrogen generation in the presence of a suitable catalyst. Homogeneous catalysts have been extensively studied and utilized for highly active and selective processes compared to conventional heterogeneous catalysis, which often shows lower reactivity and selectivity. However, the latter is preferred for practical applications, considering its easy separation and recyclability.

Breaking linear scaling relationships in oxygen evolution via dynamic structural regulation of active sites.

The universal linear scaling relationships between the adsorption energies of reactive intermediates limit the performance of catalysts in multi-step catalytic reactions. Here, we show how these scaling relationships can be circumvented in electrochemical oxygen evolution reaction by dynamic structural regulation of active sites. We construct a model Ni-Fe molecular catalyst via in situ electrochemical activation, which is able to deliver a notable intrinsic oxygen evolution reaction activity.

Transition Metal Carbonitride MXenes Anchored with Pt Sub-Nanometer Clusters to Achieve High-Performance Hydrogen Evolution Reaction at All pH Range.

Transition metal carbides, known as MXenes, particularly TiCT, have been extensively explored as promising materials for electrochemical reactions. However, transition metal carbonitride MXenes with high nitrogen content for electrochemical reactions are rarely reported. In this work, transition metal carbonitride MXenes incorporated with Pt-based electrocatalysts, ranging from single atoms to sub-nanometer dimensions, are explored for hydrogen evolution reaction (HER).

Efficient Nitrate to Ammonia Conversion on Bifunctional IrCu Alloy Nanoparticles.

Electrochemical nitrate reduction (NORR) to ammonia presents a promising alternative strategy to the traditional Haber-Bosch process. However, the competitive hydrogen evolution reaction (HER) reduces the Faradaic efficiency toward ammonia, while the oxygen evolution reaction (OER) increases the energy consumption. This study designs IrCu alloy nanoparticles as a bifunctional catalyst to achieve efficient NORR and OER while suppressing the unwanted HER.

Atomic Gap-State Engineering of MoS for Alkaline Water and Seawater Splitting.

Transition-metal dichalcogenides (TMDs), such as molybdenum disulfide (MoS), have emerged as a generation of nonprecious catalysts for the hydrogen evolution reaction (HER), largely due to their theoretical hydrogen adsorption energy close to that of platinum. However, efforts to activate the basal planes of TMDs have primarily centered around strategies such as introducing numerous atomic vacancies, creating vacancy-heteroatom complexes, or applying significant strain, especially for acidic media. These approaches, while potentially effective, present substantial challenges in practical large-scale deployment.

Designer topological-single-atom catalysts with site-specific selectivity.

Designing catalysts with well-defined, identical sites that achieve site-specific selectivity, and activity remains a significant challenge. In this work, we introduce a design principle of topological-single-atom catalysts (T-SACs) guided by density functional theory (DFT) and Ab initio molecular dynamics (AIMD) calculations, where metal single atoms are arranged in asymmetric configurations that electronic shield topologically misorients d orbitals, minimizing unwanted interactions between reactants and the support surface. Mn/CeO catalysts, synthesized via a charge-transfer-driven approach, demonstrate superior catalytic activity and selectivity for NO removal.

Valence Electron: A Descriptor of Spinel Sulfides for Sulfur Reduction Catalysis.

Catalysts are essential for achieving high-performance lithium-sulfur batteries. The precise design and regulation of catalytic sites to strengthen their efficiency and robustness remains challenging. In this study, spinel sulfides and catalyst design principles through element doping are investigated.

Critical Role of Tetrahedral Coordination in Determining the Polysulfide Conversion Efficiency on Spinel Oxides.

Understanding the structure-property relationship and the way in which catalysts facilitate polysulfide conversion is crucial for the rational design of lithium-sulfur (Li-S) battery catalysts. Herein, a series of NiAlO, CoAlO, and CuAlO spinel oxides with varying Ni, Co, or Cu tetrahedral and octahedral site occupancy are studied as Li-S battery catalysts. Combined with experimental and theoretical analysis, the tetrahedral site is identified as the most active site for enhancing polysulfide adsorption and charge transfer.

Packing Engineering of Zirconium Metal-Organic Cages in Mixed Matrix Membranes for CO/CH Separation.

Metal-organic cages (MOCs) have been considered as emerging zero-dimensional (0D) porous fillers to generate molecularly homogeneous MOC-based membrane materials. However, the discontinuous pore connectivity and low filler concentrations limit the improvement of membrane separation performance. Herein, we propose the dimension augmentation of MOCs in membranes using three-dimensional (3D) supramolecular MOC networks as filler materials in mixed matrix membranes (MMMs).

Unconventional hexagonal open Prussian blue analog structures.

Prussian blue analogs (PBAs), as a classical kind of microporous materials, have attracted substantial interests considering their well-defined framework structures, unique physicochemical properties and low cost. However, PBAs typically adopt cubic structure that features small pore size and low specific surface area, which greatly limits their practical applications in various fields ranging from gas adsorption/separation to energy conversion/storage and biomedical treatments. Here we report the facile and general synthesis of unconventional hexagonal open PBA structures.

Pt/IrO enables selective electrochemical C-H chlorination at high current.

Employing electrochemistry for the selective functionalization of liquid alkanes allows for sustainable and efficient production of high-value chemicals. However, the large potentials required for C(sp)-H bond functionalization and low water solubility of such alkanes make it challenging. Here we discover that a Pt/IrO electrocatalyst with optimized Cl binding energy enables selective generation of Cl free radicals for C-H chlorination of alkanes.

Boosting the Performance of Iridium Single Atom Catalyst in a Porous Organic Polymer for Glycerol Conversion to Lactic Acid.

Single-atom catalysts (SACs) inherit the merit of both homogeneous and heterogeneous systems with atomically dispersed mononuclear metal centers on the solid supports. Herein, we developed an Ir-SAC catalyst via the polymerization of an active homogeneous 2-picolinylhydrazone ligand-based iridium (Ir) metal complex. Such catalysts provide great stabilization against migration and agglomeration due to the strong covalent C-C bond linkage of active complexes and the polymer matrix.

Boosting C Alcohols Selectivity and Activity in High-Current CO Electroreduction using Synergistic Cu/Zn Co-Catalysts.

The electrosynthesis of multi-carbon (C) alcohols, specifically ethanol and n-propanol through CO electroreduction (CORR) in HO, presents a sustainable pathway for intermittent renewable energy storage and a low-carbon economy. However, achieving high selectivity for alcohol production at industrial current densities is kinetically hampered by side reactions such as ethylene generation and hydrogen evolution reaction, which result from competing adsorption of *CO and *H. In this study, we developed a Cu/Zn alloy catalyst to simultaneously enhance the activity and selectivity for alcohol production by increasing CO capture capacity and enriching active hydrogen on Cu sites.

Cooperative Active Sites on AgPtTiS for Enhanced Low-Temperature Ammonia Fuel Cell Electrocatalysis.

Ammonia has attracted considerable interest as a hydrogen carrier that can help decarbonize global energy networks. Key to realizing this is the development of low temperature ammonia fuel cells for the on-demand generation of electricity. However, the efficiency of such systems is significantly impaired by the sluggish ammonia oxidation reaction (AOR) and oxygen reduction reaction (ORR).

Hydrothermal-Induced Cationic Vacancies in NiAl Hydroxide for Enhanced Oxygen Evolution Activities through Optimization of e* Band Broadening.

Nickel-based hydroxides [Ni(OH)] have attracted significant attention as effective oxygen evolution reaction (OER) catalysts. In recent years, defect engineering has been extensively utilized in Ni(OH) modification research. Numerous studies have confirmed that the generation of defects can expose more active sites and regulate electronic states, particularly through the introduction of Al cationic vacancies, which enhance conductivity and thereby improve the catalytic performance.

Bioinspired Homonuclear Diatomic Iron Active Site Regulation for Efficient Antifouling Osmotic Energy Conversion.

Membrane-based reverse electrodialysis is globally recognized as a promising technology for harnessing osmotic energy. However, its practical application is greatly restricted by the poor anti-fouling ability of existing membrane materials. Inspired by the structural and functional models of natural cytochrome c oxidases (CcO), the first use of atomically precise homonuclear diatomic iron composites as high-performance osmotic energy conversion membranes with excellent anti-fouling ability is demonstrated.

A Solid-State Electrolyte Facilitates Acidic CO Electrolysis without Alkali Metal Cations by Regulating Proton Transport.

Electrochemical CO reduction (COR) in acidic media provides a pathway to curtail CO losses by suppressing the formation of (bi)carbonates. In such systems, a high concentration of alkali metal cations is necessary for mitigating the proton-rich environment and suppressing the competing hydrogen evolution reaction. However, a high cation concentration also promotes salt precipitation within the gas diffusion layer, resulting in poor system durability.

Regulating the Electrochemical Nitrate Reduction Performance with Controllable Distribution of Unconventional Phase Copper on Alloy Nanostructures.

Electrochemical nitrate reduction reaction (NORR) is emerging as a promising strategy for nitrate removal and ammonia (NH) production using renewable electricity. Although great progresses have been achieved, the crystal phase effect of electrocatalysts on NORR remains rarely explored. Here, the epitaxial growth of unconventional 2H Cu on hexagonal close-packed (hcp) IrNi template, resulting in the formation of three IrNiCu@Cu nanostructures, is reported.

Potential-driven structural distortion in cobalt phthalocyanine for electrocatalytic CO/CO reduction towards methanol.

Cobalt phthalocyanine immobilized on carbon nanotube has demonstrated appreciable selectivity and activity for methanol synthesis in electrocatalytic CO/CO reduction. However, discrepancies in methanol production selectivity and activity between CO and CO reduction have been observed, leading to inconclusive mechanisms for methanol production in this system. Here, we discover that the interaction between cobalt phthalocyanine molecules and defects on carbon nanotube substrate plays a key role in methanol production during CO/CO electroreduction.

Covalent Organic Framework Stabilized Single CoNCl Site Boosts Photocatalytic CO Reduction into Tunable Syngas.

Solar carbon dioxide (CO) reduction provides an attractive alternative to producing sustainable chemicals and fuel. However, the construction of a highly active photocatalyst was challenging because of the rapid charge recombination and sluggish surface CO reduction. Herein, a unique Co-NCl single site was fabricated by loading Co species into the 2,2'-bipyridine and triazine-containing covalent organic framework (COF) for CO conversion into syngas under visible light irradiation.