Azo-Enhanced Raman Scattering Probing Proton Transfer between Water and Nanoscale Zero-valent Iron.

The interaction between a solid and water at their interface, especially proton transfer, impacts molecular-scale catalysis, macroscopic environmental science, and geoscience. Although being highly desired, directly probing proton transfer between a solid and water is a great challenge, given the subnanometer to nanometer scale of the interface. The fundamental challenge lies in the lack of a measurement tool to sensitively observe local proton concentration without introducing an exogenous electrode or nanoparticle with a minimum size of tens of nanometers.

Reversed ICu single-atom sites for superior neutral ammonia electrosynthesis with nitrate.

Electrochemical ammonia (NH) synthesis from nitrate reduction (NITRR) offers an appealing solution for addressing environmental concerns and the energy crisis. However, most of the developed electrocatalysts reduce NO to NH via a hydrogen (H*)-mediated reduction mechanism, which suffers from undesired H*-H* dimerization to H, resulting in unsatisfactory NH yields. Herein, we demonstrate that reversed ICu single-atom sites, prepared by anchoring iodine single atoms on the Cu surface, realized superior NITRR with a superior ammonia yield rate of 4.

Superior Singlet Oxygen Electrosynthesis via Neighboring Dual Molecular Oxygen Coactivation for Selective Tetracycline Detoxification.

Oxygen (O) electroreduction offers a green approach for singlet oxygen (O) synthesis in wastewater contaminants detoxification. However, traditional single O activation on single-metal catalytic sites seriously suffers from the kinetically-unfavorable desorption of adsorbed superoxide species (•O */•OOH*). Here, we demonstrate a novel dual O coactivation pathway on shortened Fe-O-Ti sites for superior O electrosynthesis through a rapid disproportionate process between surface-confined •O */•OOH*.

Asymmetric Ru-In atomic pairs promote highly active and stable acetylene hydrochlorination.

Ru single-atom catalysts have great potential to replace toxic mercuric chloride in acetylene hydrochlorination. However, long-term catalytic stability remains a grand challenge due to the aggregation of Ru atoms caused by over-chlorination. Herein, we synthesize an asymmetric Ru-In atomic pair with vinyl chloride monomer yield (>99.

Highly selective urea electrooxidation coupled with efficient hydrogen evolution.

Electrochemical urea oxidation offers a sustainable avenue for H production and wastewater denitrification within the water-energy nexus; however, its wide application is limited by detrimental cyanate or nitrite production instead of innocuous N. Herein we demonstrate that atomically isolated asymmetric Ni-O-Ti sites on Ti foam anode achieve a N selectivity of 99%, surpassing the connected symmetric Ni-O-Ni counterparts in documented Ni-based electrocatalysts with N selectivity below 55%, and also deliver a H evolution rate of 22.0 mL h when coupled to a Pt counter cathode under 213 mA cm at 1.

Fluorine Modification Promoted Water Dissociation into Atomic Hydrogen on a Copper Electrode for Efficient Neutral Nitrate Reduction and Ammonia Recovery.

Electrocatalytic nitrate reduction to ammonia (NITRR) offers an attractive solution for alleviating environmental concerns, yet in neutral media, it is challenging as a result of the reliance on the atomic hydrogen (H*) supply by breaking the stubborn HO-H bond (∼492 kJ/mol) of HO. Herein, we demonstrate that fluorine modification on a Cu electrode (F-NFs/CF) favors the formation of an O-H···F hydrogen bond at the Cu-HO interface, remarkably stretching the O-H bond of HO from 0.98 to 1.

Monodispersed and Organic Amine Modified La(OH) Nanocrystals for Superior Advanced Phosphate Removal.

Advanced phosphate removal is critical for alleviating the serious and widespread aquatic eutrophication, strongly depending on the development of superior adsorption materials to overcome low chemical affinity and sluggish mass transfer at low phosphate concentrations. Herein, the first synthesis of monodispersed and organic amine modified lanthanum hydroxide nanocrystals (OA-La(OH)) for advanced phosphate removal by modulating inner Helmholtz plane (IHP), is reported. These OA-La(OH) nanocrystals with positively charged surfaces and abundant exposed La sites exhibit specific affinity toward phosphate, delivering a maximum adsorption capacity of 168 mg P g⁻ and a wide pH adaptability from 3.

Engineering the Coordination Environment of Ir Single Atoms with Surface Titanium Oxide Amorphization for Superior Chlorine Evolution Reaction.

The chlorine evolution reaction (CER) is essential for industrial Cl production but strongly relies on the use of dimensionally stable anode (DSA) with high-amount precious Ru/Ir oxide on a Ti substrate. For the purpose of sustainable development, precious metal decrement and performance improvement are highly desirable for the development of CER anodes. Herein, we demonstrate that surface titanium oxide amorphization is crucial to regulate the coordination environment of stabilized Ir single atoms for efficient and durable chlorine evolution of Ti monolithic anodes.

Cobalt Single-Atom Reverse Hydrogen Spillover for Efficient Electrochemical Water Dissociation and Dechlorination.

Efficient water dissociation to atomic hydrogen (H*) with restrained recombination of H* is crucial for improving the H* utilization for electrochemical dechlorination, but is currently limited by the lack of feasible electrodes. Herein, we developed a monolithic single-atom electrode with Co single atoms anchored on the inherent oxide layer of titanium foam (Co-TiO/Ti), which can efficiently dissociate water into H* and simultaneously inhibit the recombination of H*, by taking advantage of the single-atom reverse hydrogen spillover effect. Experimental and theoretical calculations demonstrated that H* could be rapidly generated on the oxide layer of titanium foam, and then overflowed to the adjacent Co single atom for the reductive dechlorination.

Spin polarized Fe-Ti pairs for highly efficient electroreduction nitrate to ammonia.

Electrochemical nitrate reduction to ammonia offers an attractive solution to environmental sustainability and clean energy production but suffers from the sluggish *NO hydrogenation with the spin-state transitions. Herein, we report that the manipulation of oxygen vacancies can contrive spin-polarized Fe-Ti pairs on monolithic titanium electrode that exhibits an attractive NH yield rate of 272,000 μg h mg and a high NH Faradic efficiency of 95.2% at -0.

Renewable energy driven electroreduction nitrate to ammonia and in-situ ammonia recovery via a flow-through coupled device.

Green ammonia production from wastewater via electrochemical nitrate reduction contributes substantially to the realization of carbon neutrality. Nonetheless, the current electrochemical technology is largely limited by the lack of suitable device for efficient and continuous electroreduction nitrate into ammonia and in-situ ammonia recovery. Here, we report a flow-through coupled device composed of a compact electrocatalytic cell for efficient nitrate reduction and a unit to separate the produced ammonia without any pH adjustment and additional energy-input from the circulating nitrate-containing wastewater.

Single Atom Ru Monolithic Electrode for Efficient Chlorine Evolution and Nitrate Reduction.

Fabricating single-atom electrodes via atomic dispersion of active metal atoms into monolithic metal supports is of great significance to advancing the lab-to-fab translation of the electrochemical technologies. Here, we report an inherent oxide anchoring strategy to fasten ligand-free isolated Ru atoms on the amorphous layer of monolithic Ti support by regulating the electronic metal-support interactions. The prepared Ru single atom electrode exhibited exceptional electrochemical chlorine evolution activity, three orders of magnitude higher mass activity than that of commercial dimensionally stable anode, and also selectively reduced nitrate to ammonia with an unprecedented ammonia yield rate of 22.

Recover the activity of sintered supported catalysts by nitrogen-doped carbon atomization.

The sintering of supported metal nanoparticles is a major route to the deactivation of industrial heterogeneous catalysts, which largely increase the cost and decrease the productivity. Here, we discover that supported palladium/gold/platinum nanoparticles distributed at the interface of oxide supports and nitrogen-doped carbon shells would undergo an unexpected nitrogen-doped carbon atomization process against the sintering at high temperatures, during which the nanoparticles can be transformed into more active atomic species. The in situ transmission electron microscopy images reveal the abundant nitrogen defects in carbon shells provide atomic diffusion sites for the mobile atomistic palladium species detached from the palladium nanoparticles.

Engineering the Electronic Structure of Submonolayer Pt on Intermetallic PdPb via Charge Transfer Boosts the Hydrogen Evolution Reaction.

The efficient electrochemical hydrogen evolution reaction (HER) plays a key role in accelerating sustainable H production from water electrolysis, but its large-scale applications are hindered by the high cost of the state-of-the-art Pt catalyst. In this work, submonolayer Pt was controllably deposited on an intermetallic PdPb nanoplate (AL-Pt/PdPb). The atomic efficiency and electronic structure of the active surface Pt layer were largely optimized, greatly enhancing the acidic HER.

Modulating fcc and hcp Ruthenium on the Surface of Palladium-Copper Alloy through Tunable Lattice Mismatch.

Herein, we report an epitaxial-growth-mediated method to grow face-centered cubic (fcc) Ru, which is thermodynamically unfavorable in the bulk form, on the surface of Pd-Cu alloy. Induced by the galvanic replacement between Ru and Pd-Cu alloy, a shape transformation from a Pd-Cu@Ru core-shell to a yolk-shell structure was observed during the epitaxial growth. The successful coating of the unconventional crystallographic structure is critically dependent on the moderate lattice mismatch between the fcc Ru overlayer and PdCu3 alloy substrate.