Precise Regulation of In Situ Exsolution Components of Nanoparticles for Constructing Active Interfaces toward Carbon Dioxide Reduction.

Metal nanocatalysts supported on oxide scaffolds have been widely used in energy storage and conversion reactions. So far, the main research is still focused on the growth, density, size, and activity enhancement of exsolved nanoparticles (NPs). However, the lack of precise regulation of the type and composition of NPs elements under reduction conditions has restricted the architectural development of in situ exsolution systems.

Designed Synthesis of Mesoporous sp Carbon-Conjugated Benzothiadiazole Covalent Organic Frameworks for Artificial Photosynthesis of Hydrogen Peroxide.

Artificial photosynthesis of hydrogen peroxide (HO) from ambient air, water, and sunlight has attracted considerable attention recently. Despite being extremely challenging to synthesis, sp carbon-conjugated covalent organic frameworks (COFs) can be powerful and efficient materials for the photosynthesis of HO due to desirable properties. Herein, we report the designed synthesis of an sp carbon-conjugated COF, BTD-spc-COF, from benzothiadiazole and triazine units with high crystallinity and ultralarge mesopores (∼4 nm).

Bioinspired catalytic pocket promotes CO-to-ethanol photoconversion on colloidal quantum wells.

Sluggish surface reaction is a critical factor that strongly governs the efficiency of photocatalytic solar fuel production, particularly in CO-to-ethanol photoconversion. Here, inspired by the principles underlying enzyme catalytic proficiency and specificity, we report a biomimetic photocatalyst that affords superior CO-to-ethanol photoreduction efficiency (5.5 millimoles gram hour in average with 98.

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.

Dimethyl Carbonate Synthesis from CO over CeO with Electron-Enriched Lattice Oxygen Species.

Direct synthesis of dimethyl carbonate (DMC) from CO plays an important role in carbon neutrality, but its efficiency is still far from the practical application, due to the limited understanding of the reaction mechanism and rational design of efficient catalyst. Herein, abundant electron-enriched lattice oxygen species were introduced into CeO catalyst by constructing the point defects and crystal-terminated phases in the crystal reconstruction process. Benefitting from the acid-base properties modulated by the electron-enriched lattice oxygen, the optimized CeO catalyst exhibited a much higher DMC yield of 22.

Expanding Olefin-Linked Covalent Organic Frameworks toward Selective Photocatalytic Oxidation of Organic Sulfides.

Olefin-linked covalent organic frameworks (COFs) have exhibited great potential in visible-light photocatalysis. In principle, expanding fully conjugated COFs can facilitate light absorption and charge transfer, leading to improved photocatalysis. Herein, three olefin-linked COFs with the same topology are synthesized by combining 2,4,6-trimethyl-1,3,5-triazine (TMT) with 1,3,5-triformylbenzene (TFB), 1,3,5-tris(4-formylphenyl)benzene (TFPB), and 1,3,5-tris(4-formylphenylethynyl)benzene (TFPEB), namely, TMT-TFB-COF, TMT-TFPB-COF, and TMT-TFPEB-COF, respectively.

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.

Insights into the Diffusion Behaviors of Water over Hydrophilic/Hydrophobic Catalysts During the Conversion of Syngas to High-Quality Gasoline.

Although considerable efforts towards directly converting syngas to liquid fuels through Fischer-Tropsch synthesis have been made, developing catalysts with low CO selectivity for the synthesis of high-quality gasoline remains a big challenge. Herein, we designed a bifunctional catalyst composed of hydrophobic FeNa@Si-c and HZSM-5 zeolite, which exhibited a low CO selectivity of 14.3 % at 49.

Finding Key Factors for Efficient Water and Methanol Activation at Metals, Oxides, MXenes, and Metal/Oxide Interfaces.

Activating water and methanol is crucial in numerous catalytic, electrocatalytic, and photocatalytic reactions. Despite extensive research, the optimal active sites for water/methanol activation are yet to be unequivocally elucidated. Here, we combine transition-state searches and electronic charge analyses on various structurally different materials to identify two features of favorable O-H bond cleavage in HO, CHOH, and hydroxyl: (1) low barriers appear when the charge of H moieties remains approximately constant during the dissociation process, as observed on metal oxides, MXenes, and metal/oxide interfaces.

Fine cubic CuO nanocrystals as highly selective catalyst for propylene epoxidation with molecular oxygen.

Propylene epoxidation with O to propylene oxide is a very valuable reaction but remains as a long-standing challenge due to unavailable efficient catalysts with high selectivity. Herein, we successfully explore 27 nm-sized cubic CuO nanocrystals enclosed with {100} faces and {110} edges as a highly selective catalyst for propylene epoxidation with O, which acquires propylene oxide selectivity of more than 80% at 90-110 °C. Propylene epoxidation with weakly-adsorbed O species at the {110} edge sites exhibits a low barrier and is the dominant reaction occurring at low reaction temperatures, leading to the high propylene oxide selectivity.

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.

Disentangling the size-dependent geometric and electronic effects of palladium nanocatalysts beyond selectivity.

The prominent size effect of metal nanoparticles shapes decisively nanocatalysis, but entanglement of the corresponding geometric and electronic effects prevents exploiting their distinct functionalities. In this work, we demonstrate that in palladium (Pd)-catalyzed aerobic oxidation of benzyl alcohol, the geometric and electronic effects interplay and compete so intensively that both activity and selectivity showed in volcano trends on the Pd particle size unprecedentedly. By developing a strategy of site-selective blocking via atomic layer deposition along with first principles calculations, we disentangle these two effects and unveil that the geometric effect dominates the right side of the volcano with larger-size Pd particles, whereas the electronic effect directs the left of the volcano with smaller-size Pd particles substantially.

Efficient Oxygen Electrocatalysis by Nanostructured Mixed-Metal Oxides.

Oxygen electrocatalysis plays a critical role in the efficiency of important energy conversion and storage systems. While many efforts have focused on designing efficient electrocatalysts for these processes, optimal catalysts that are inexpensive, active, selective, and stable are still being searched. Nonstoichiometric, mixed-metal oxides present a promising group of electrocatalysts for these processes due to the versatility of the surface composition and fast oxygen conducting properties.

Trimethylaluminum and Oxygen Atomic Layer Deposition on Hydroxyl-Free Cu(111).

Atomic layer deposition (ALD) of alumina using trimethylaluminum (TMA) has technological importance in microelectronics. This process has demonstrated a high potential in applications of protective coatings on Cu surfaces for control of diffusion of Cu in Cu2S films in photovoltaic devices and sintering of Cu-based nanoparticles in liquid phase hydrogenation reactions. With this motivation in mind, the reaction between TMA and oxygen was investigated on Cu(111) and Cu2O/Cu(111) surfaces.

Atomic layer deposition overcoating: tuning catalyst selectivity for biomass conversion.

The terraces, edges, and facets of nanoparticles are all active sites for heterogeneous catalysis. These different active sites may cause the formation of various products during the catalytic reaction. Here we report that the step sites of Pd nanoparticles (NPs) can be covered precisely by the atomic layer deposition (ALD) method, whereas the terrace sites remain as active component for the hydrogenation of furfural.

Crystal-plane-controlled selectivity of Cu(2)O catalysts in propylene oxidation with molecular oxygen.

The selective oxidation of propylene with O2 to propylene oxide and acrolein is of great interest and importance. We report the crystal-plane-controlled selectivity of uniform capping-ligand-free Cu2 O octahedra, cubes, and rhombic dodecahedra in catalyzing propylene oxidation with O2 : Cu2 O octahedra exposing {111} crystal planes are most selective for acrolein; Cu2 O cubes exposing {100} crystal planes are most selective for CO2 ; Cu2 O rhombic dodecahedra exposing {110} crystal planes are most selective for propylene oxide. One-coordinated Cu on Cu2 O(111), three-coordinated O on Cu2 O(110), and two-coordinated O on Cu2 O(100) were identified as the catalytically active sites for the production of acrolein, propylene oxide, and CO2 , respectively.

CO oxidation at the perimeters of an FeO/Pt(111) interface and how water promotes the activity: a first-principles study.

The catalytic role of the Pt--Fe cation ensemble presented at the perimeters of the FeO film supported on Pt(111) for low-temperature CO oxidation and the promotion of water on activity were studied by using DFT calculations. We found that the perimeter sites along the edge of the FeO islands on Pt provided a favorable ensemble that consisted of coordinatively unsaturated ferrous species and nearby Pt atoms for O(2) and H(2) O activation free from CO poison. A dissociative oxygen atom at the Pt--Fe cation ensemble reacts easily with CO adsorbed on nearby Pt.

Interface-confined ferrous centers for catalytic oxidation.

Coordinatively unsaturated ferrous (CUF) sites confined in nanosized matrices are active centers in a wide range of enzyme and homogeneous catalytic reactions. Preparation of the analogous active sites at supported catalysts is of great importance in heterogeneous catalysis but remains a challenge. On the basis of surface science measurements and density functional calculations, we show that the interface confinement effect can be used to stabilize the CUF sites by taking advantage of strong adhesion between ferrous oxides and metal substrates.