SrZnSiS: Shattering the 4.0 eV Threshold toward Dual-Optimized Bandgap and Second-Harmonic Generation.

Infrared (IR) nonlinear optical (NLO) crystals are crucial for mid-IR lasers, yet their intrinsic narrow band gaps cause low laser-induced damage thresholds (LIDTs) and detrimental two-photon absorption, thus limiting their widespread application. Herein, a synergistic strategy involving d-orbital exclusion and polarization motif construction is employed to synthesize novel chalcogenide SrZnSiS by introducing [SiS] and [ZnS] tetrahedral polarization subunits. Performance evaluation demonstrates that SrZnSiS breaks through the "4.

Directed protonation strategy for efficient electrochemical metaborate reduction to sodium borohydride at the interface of manganese single atoms and manganese oxide nanoparticles.

Sodium borohydride (NaBH) is considered as an outstanding hydrogen generation and storage material, whereas its widespread commercial application remains hindered by prohibitively high production cost and unsatisfied yield in the current production process. Electrochemical metaborate reduction reaction is a promising method to realize the low-cost and effective NaBH production, where the *H generation and the inhibition of HH coupling are critical but still remain challenging for suppressing competing hydrogen evolution reaction (HER). Herein, a core-shell structure with manganese oxide as a core and manganese single atom coordinated by nitrogen on the carbon substrate as a shell (MnO@Mn-N-C) was synthesized, where Mn-N-C enabled to boost water dissociation and electron donating as well as suppress HH coupling, thereby enhancing directed hydrogenation of reaction intermediate to generate NaBH.

Promoting electrocatalytic CO reduction to -propanol over ethanol at Cu step sites.

Obtaining valuable C products directly from the electrocatalytic reduction of CO or CO is an attractive but challenging task, due to the much more complicated reaction pathways and sluggish kinetics of C products than their C and C counterparts. As different C products and competitive C side-products may share the common rate-determining step ( the carbon-carbon coupling), the regulation of subsequent selectivity-determining step(s) is critical for promoting the selectivity of C products. Herein, we focused on tuning the selectivity competition between -propanol (-CHOH, an important C alcohol) ethanol (CHOH, a major C side product), based on the constant potential computations on the Cu surface with different step sites.

Switching Photocatalytic Methane Oxidation Toward Ethanol by Tuning Spin States.

The selective oxidation of methane (CH) has attractive potentials for mitigating global warming and producing value-added chemicals, whereas the efficient generation of multicarbon products such as ethanol remains challenging, due to the short lifetimes and high unpaired concentrations of reactive intermediates (like •OH, •CH, •OCH, and •CHOH). Herein, we developed a medium-spin Zn-O-Fe(MS) catalyst with tunable Fe(III) spin states, which can efficiently photo-oxidize CH to ethanol at ambient conditions. The unpaired electrons in d orbitals of Fe sites allow for efficient adsorption of •OH, and the e orbital occupancy enables stabilizing different key carbon-containing intermediates (•OCH versus •CHOH).

B-Site-Metal-Mediated Coke-Resistant CO Electrolysis on Perovskite Surfaces.

High-temperature CO reduction to CO using perovskite-oxide-based solid oxide electrochemical cells holds promise for carbon-neutral chemical production, yet currently faces the challenge of coke formation that leads to device failure. A key reason behind this challenge is the absence of a correlation between the coke formation mechanism and perovskite structures. Here, lanthanum strontium cobalt ferrite perovskites are taken with a classical ABO structure as examples to study coke formation on them and unravel the dependence of coke resistance on the Fe stoichiometry.

Selective Urea Electrosynthesis from CO and Nitrate on Spin-Polarized Atomically Ordered PdCuCo.

The electrocatalytic conversion of NO and CO into urea features a potential means of reducing carbon footprint and generating value-added chemicals. Nonetheless, due to the limited efficiency of carbon-nitrogen (C─N) coupling and the competing side reaction that forms ammonia, the urea selectivity and production yield have remained low. In this work, a spin-polarized cobalt-doped, atomically ordered PdCu intermetallic compound (denoted as PdCuCo) is developed as an efficient urea electrosynthesis catalyst.

Low-Coordination Triangular Cu Motif Steers CO Photoreduction to Ethanol.

Photoreduction of CO using copper-based multi-atom catalysts (MACs) offers a potential approach to achieve value-added C products. However, achieving MACs with high metal contents and suppressing the thermodynamically favored competing ethylene production pathway remain challenging, thus leading to unsatisfactory performance in ethanol production. Herein, we developed a "pre-locking and nanoconfined polymerization" strategy for synthesis of an ultra-high-density Cu MAC with low-coordination triangular Cu motifs (Cu MAC) on polymeric carbon nitride mesoporous nanofibers.

p-π Conjugated Covalent Organic Frameworks Expedite Molecular Triplet Excitons for HO Production Coupled with Biomass Upgrading.

High-efficiency production of triplet states in covalent organic framework photocatalysts is crucial for high-selectivity oxygen (O) reduction to hydrogen peroxide (HO). Herein, fluorine and partial fluorine atoms are incorporated into an olefin-linked triazine covalent organic framework (F-ol-COF and HF-ol-COF), in which the adjacent fluorine (F) atoms-olefinic bond forms p-π conjugation that induces spin-polarization under irradiation, thus expediting triplet excitons for activating O to singlet oxygen (O) and contributing to a high HO selectivity (91%). Additionally, the feasibility of coupling HO production with the valorization of 5-hydroxymethylfurfural (HMF) is exhibited.

Hydrogen-Bond-Assisted Electrocatalytic Semi-Oxidation of 5-Hydroxymethylfurfural into 2,5-Diformylfuran by Operando Dissociated N-Oxyl Mediator.

The conversion of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) is a promising approach for enhancing biomass utilization. Nevertheless, traditional methods using noble metal catalysts face challenges due to high costs and poor selectivity towards DFF. Herein, we developed a novel catalytic electrode integrating N-hydroxyphthalimide (NHPI) into a metal-organic framework on a hydrophilic carbon cloth.

Electrokinetic Analysis-Driven Promotion of Electrocatalytic CO Reduction to n-Propanol.

The electrocatalytic carbon dioxide or carbon monoxide reduction reaction (CORR or CORR) features a sustainable method for reducing carbon emissions and producing value-added chemicals. However, the generation of C products with higher energy density and market values, such as n-propanol, remains highly challenging, which is attributed to the unclear formation mechanism of C versus C products. In this work, by the Tafel slope analysis, electrolyte pH correlation exploration, and the kinetic analysis of CO partial pressure fitting, it is identified that both n-propanol and C products share the same rate-determining step, which is the coupling of two C intermediates via the derivation of the Butler-Volmer equation.

Unconventional Electrocatalytic CO Conversion to C Products on Single-Atomic Pd-Ag Sites.

The electrochemical reduction of CO or CO into C products has mostly been focused on Cu-based catalysts. Although Ag has also been predicted as a possible catalyst for the CO-to-C conversion from the thermodynamic point of view, however, due to its weak CO binding strength, CO rapidly desorbs from the Ag surface rather than participates in deep reduction. In this work, we demonstrate that single-atomic Pd sites doped in Ag lattice can tune the CO adsorption behavior and promote the deep reduction of CO toward C products.

Pd-induced polarized Cu-Cu sites for electrocatalytic CO-to-C conversion in acidic medium.

The acidic CO reduction reaction (CORR) offers a promising approach to mitigate CO reactant loss and carbonate deposition, which are challenging issues in alkaline or neutral electrolytes. However, the hydrogen evolution reaction (HER) competes in the proton-rich environment near the catalyst surface as a side reaction, reducing the energy efficiency of generating multi-carbon (C) products. In this work, we proposed a palladium (Pd) doping strategy in a copper (Cu)-based catalyst to stabilize polarized Cu-Cu sites, thus enhancing the CC coupling step during the CORR while suppressing HER.

Switching CO Electroreduction toward Ethanol by Delocalization State-Tuned Bond Cleavage.

The electrochemical CO reduction reaction by copper-based catalysts features a promising approach to generate value-added multicarbon (C) products. However, due to the unfavored formation of oxygenate intermediates on the catalyst surface, the selectivity of C alcohols like ethanol remains unsatisfactory compared to that of ethylene. The bifurcation point (i.

Electrocatalytic Glycerol Upgrading into Glyceric Acid on NiSn Intermetallic Compound.

Electrochemical glycerol oxidation features an attractive approach of converting bulk chemicals into high-value products such as glyceric acid. Nonetheless, to date, the major product selectivity has mostly been limited as low-value C products such as formate, CO, and CO, due to the fast cleavage of carbon-carbon (C-C) bonds during electro-oxidation. Herein, the study develops an atomically ordered NiSn intermetallic compound catalyst, in which Sn atoms with low carbon-binding and high oxygen-binding capability allow to tune the adsorption of glycerol oxidation intermediates from multi-valent carbon binding to mono-valent carbon binding, as well as enhance OH binding and subsequent nucleophilic attack.

Weak-Field Electro-Flash Induced Asymmetric Catalytic Sites toward Efficient Solar Hydrogen Peroxide Production.

Borocarbonitride (BCN), in a mesoscopic asymmetric state, is regarded as a promising photocatalyst for artificial photosynthesis. However, BCN materials reported in the literature primarily consist of symmetric N-[B] units, which generate highly spatial coupled electron-hole pairs upon irradiation, thus kinetically suppressing the solar-to-chemical conversion efficiency. Here, we propose a facile and fast weak-field electro-flash strategy, with which structural symmetry breaking is introduced on key nitrogen sites.

Bipolaronic Motifs Induced Spatially Separated Catalytic Sites for Tunable Syngas Photosynthesis From CO.

Photocatalytic reduction of CO into syngas is a promising way to tackle the energy and environmental challenges; however, it remains a challenge to achieve reaction decoupling of CO reduction and water splitting. Therefore, efficient production of syngas with a suitable CO/H ratio for Fischer-Tropsch synthesis can hardly be achieved. Herein, bipolaronic motifs including Co(II)-pyridine N motifs and Co(II)-imine N motifs are rationally designed into a crystalline imine-linked 1,10-phenanthroline-5,6-dione-based covalent organic framework (bp-Co-COF) with a triazine core.

Anthraquinone-Induced asymmetric antimony coordination center for selective O photoreduction to HO.

Achieving O photoreduction to HO with high selectivity control and durability while using easily accessible catalyst requires new synthesis strategies. Herein, we propose an asymmteric Sb coordination active center strategy of introducing anthraquinone (AQ) and heptazine to form local N - Sb - O coordination by a rapid and simple explosive crystallization approach, resulting in a mesoporous conjugated heptazine-amide-AQ polymer coordinated Sb (HAAQ-Sb). It is demonstrated that the N - Sb - O coordination effectively suppresses the charge recombination and acts as the highly active site for O adsorption.

Custom-Design of Strong Electron/Proton Extractor on COFs for Efficient Photocatalytic HO Production.

The development of photocatalysts with continuous electron extraction and rapid proton transfer could kinetically accelerate the artificial photosynthesis, but remains a challenge. Herein, we report the topology-guided synthesis of a high-crystalline triazine covalent organic framework (COF) decorated by uniformly distributed polar oxygen functional groups (sulfonic group or carboxyl) as the strong electron/proton extractor for efficient photocatalytic HO production. It was found that the polarity-based proton transfer as well as electron enrichment in as-obtained COFs played a crucial role in improving the HO photosynthesis efficiency (i.

Tailoring the CO and H Coverage for Selective CO Electroreduction to CH or CH.

In the electrochemical CO reduction reaction (CORR), the coverages of CO and H intermediates on a catalyst surface are critical for the selective generation of C or C products. In this work, we have synthesized several CuZnMn ternary alloy electrocatalysts, including CuZnMn, CuZnMn, and CuZnMn, by varying the doping compositions of Zn and Mn, which are efficient in binding CO and H adsorbates in the CO electroreduction process, respectively. The increase of H coverage allows to promotion of the CH and H formation, while the increase of the CO coverage facilitates the production of CH and CO.

High-Power CO-to-C Electroreduction on Ga-Spaced, Square-like Cu Sites.

The electrochemical conversion of CO into multicarbon (C) products on Cu-based catalysts is strongly affected by the surface coverage of adsorbed CO (*CO) intermediates and the subsequent C-C coupling. However, the increased *CO coverage inevitably leads to strong *CO repulsion and a reduced C-C coupling efficiency, thus resulting in suboptimal CO-to-C activity and selectivity, especially at ampere-level electrolysis current densities. Herein, we developed an atomically ordered CuGa intermetallic compound consisting of Cu square-like binding sites interspaced by catalytically inert Ga atoms.

1D Insertion Chains Induced Small-Polaron Collapse in MoS 2D Layers Toward Fast-Charging Sodium-Ion Batteries.

Molybdenum disulfide (MoS ) with high theoretical capacity is viewed as a promising anode for sodium-ion batteries but suffers from inferior rate capability owing to the polaron-induced slow charge transfer. Herein, a polaron collapse strategy induced by electron-rich insertions is proposed to effectively solve the above issue. Specifically, 1D [MoS] chains are inserted into MoS to break the symmetry states of 2D layers and induce small-polaron collapse to gain fast charge transfer so that the as-obtained thermodynamically stable Mo S shows metallic behavior with 10 times larger electrical conductivity than that of MoS .

Photo-Driven Quasi-Topological Transformation Exposing Highly Active Nitrogen Cation Sites for Enhanced Photocatalytic H O Production.

Herein, the exposure of highly-active nitrogen cation sites has been accomplished by photo-driven quasi-topological transformation of a 1,10-phenanthroline-5,6-dione-based covalent organic framework (COF), which contributes to hydrogen peroxide (H O ) synthesis during the 2-electron O photoreduction. The exposed nitrogen cation sites with photo-enhanced Lewis acidity not only act as the electron-transfer motor to adjust the inherent charge distribution, powering continuous and stable charge separation, and broadening visible-light adsorption, but also providing a large number of active sites for O adsorption. The optimal catalyst shows a high H O production rate of 11965 μmol g  h under visible light irradiation and a remarkable apparent quantum yield of 12.

Promoting CO Electroreduction to Acetate by an Amine-Terminal, Dendrimer-Functionalized Cu Catalyst.

Acetate derived from electrocatalytic CO reduction represents a potential low-carbon synthesis approach. However, the CO-to-acetate activity and selectivity are largely inhibited by the low surface coverage of generated *CO, as well as the inefficient ethenone intermediate formation due to the side reaction between CO and alkaline electrolytes. Tuning catalyst microenvironments by chemical modification of the catalyst surface is a potential strategy to enhance CO capture and increase local *CO concentrations, while it also increases the selectivity of side reduction products, such as methane or ethylene.

Interfacial Water Tuning by Intermolecular Spacing for Stable CO Electroreduction to C Products.

Electroreduction of CO to multi-carbon (C ) products is a promising approach for utilization of renewable energy, in which the interfacial water quantity is critical for both the C product selectivity and the stability of Cu-based electrocatalytic sites. Functionalization of long-chain alkyl molecules on a catalyst surface can help to increase its stability, while it also tends to block the transport of water, thus inhibiting the C product formation. Herein, we demonstrate the fine tuning of interfacial water by surface assembly of toluene on Cu nanosheets, allowing for sustained and enriched CO supply but retarded water transfer to catalytic surface.