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A well-defined Fe-based single-atom catalyst for electrocatalytic CO2 reduction to CO was synthesized via a facile pyrolysis of Fe-doped ZIF-8. Fe single-atomic sites exhibit optimum activity in producing CO with nearly 100% faradaic efficiency.

A super anti-sintering Pt nanoparticle catalyst on LaNiO3 support is synthesized by introducing Ru ions into LaNiO3 to produce the strong interface bonding between the Pt nanoparticle catalyst and LaNiO3 support.

Developing the large-scale preparation of non-noble metal catalysts with high performance is crucial for promoting the electrochemical production of hydrogen from water. In this work, a novel TiO2@FeNi2S4 (TiO2@FNS) branch nanoflake array on Ni foam can be prepared at a large scale (50 cm2) by combining an atomic-layer-deposited (ALD) TiO2 skeleton with one-step facile low-temperature (

Proton-exchange membrane fuel cells (PEMFCs) are limited by their extreme sensitivity to trace-level CO impurities, thus setting a strict requirement for H2 purity and excluding the possibility to directly use cheap crude hydrogen as fuel. Herein, we report a proof-of-concept study, in which a novel catalyst comprising both Ir particles and Ir single-atom sites (IrNP @IrSA -N-C) addresses the CO poisoning issue. The Ir single-atom sites are found not only to be good CO oxidizing sites, but also excel in scavenging the CO molecules adsorbed on Ir particles in close proximity, thereby enabling the Ir particles to reserve partial active sites towards H2 oxidation. The interplay between Ir nanoparticles and Ir single-atom centers confers the catalyst with both excellent H2 oxidation activity (1.19 W cm-2 ) and excellent CO electro-oxidation activity (85 mW cm-2 ) in PEMFCs; the catalyst also tolerates CO in H2 /CO mixture gas at a level that is two times better than that of the current best PtRu/C catalyst.

Proton exchange membrane fuel cells (PEMFCs) suffer extreme CO poisoning even at PPM level (

The electrochemical CO

WC|WS2 composites with a sponge-like structure were constructed from nanolayers with the aid of NaCl as a template. Each nanolayer was composed of WC|WS2 interfaces by inducing carbon as the interstitial atoms. The local configuration around W atoms was probed by EXAFS. The catalytic activity of WC|WS2 composites for the hydrogen evolution reaction was thoroughly investigated by varying the ratio of WC|WS2. The sponge-like structures not only facilitate the transportation of the electrolyte, but also offer more edge active sites. The introduction of carbon provides W–C bonds, which accelerate the electron transportation and improve the stability of the catalyst in the hydrogen evolution reaction. The hybrid catalyst presents a low overpotential of 103 mV at 10 mA cm−2 and a Tafel slope of 58 mV Dec−1 and possesses great potential for low-cost and larger-scale production applied in catalysis.

A Ru single-atom (Ru SA) catalyst supported on activated carbon was adopted to synthesize 3-pentanone with 83.3% selectivity via heterogeneous ethylene hydroformylation, while 52.1% ethane selectivity was obtained for Ru nanoparticles (Ru NPs). The atomically dispersed Ru species with oxidation state (Ruδ+) and Ru-C4O coordination structure were identified as the active sites for efficient C–C coupling to generate 3-pentanone, while metallic Ru nanoparticles exhibited high activity for ethylene hydrogenation to ethane. Density functional theory (DFT) calculation revealed that the energy barrier of the direct coupling of C2H5CO* with C2H5* to form 3-pentanone on Ru SA was much lower than that on Ru NPs. As a result, the formation of 3-pentanone over Ru SA was more favourable than propanal, which was admittedly generated via coupling of C2H5CO* and H*. This strategy may provide a potential green route for the one-pot synthesis of 3-pentanone with high atomic economy.

Hydrogen economy by water splitting is the indispensable cornerstone for sustainable energy yet it is impeded by sluggish anodic water oxidation. Hence, the rational design of highly efficient electrocatalysts for oxygen evolution is the key to unlocking its wider use. Herein, cobalt–iron selenide nanoframes are reported for the efficient water oxidation, which need only 270 mV overpotential to give a 10 mA cm−2 current density and outperforms most cobalt-based catalysts, and even the benchmarked commercial ruthenium oxides (RuO2). More profoundly, iron doping regulates the local spin state of cobalt species, which further accelerates charge transfer and formation of oxygenated intermediates, and consequently contributes to the enhanced oxygen evolution. This work demonstrates a highly efficient oxygen evolution electrocatalyst and may pioneer a promising approach which involves tuning the local electronic structure to achieve the improved electrocatalysis activities in energy conversion technologies.

Development of efficient and affordable catalytic systems for direct H2O2 production from abundant resources is necessary to replace the current anthraquinone process and also to enable broader use...

Catalytic conversion of the syngas into higher alcohols (HAs) via Fischer–Tropsch (F–T) synthesis is essential due to the widespread applications of HAs. The interfaces of cobalt and cobalt carbide (Co2C) are found to efficiently promote the HAs formation. However, the study on the links between structural evolution of Co–Co2C interfaces and HAs production is still lacking. In this work, Co3O4 with different contents of sodium (Na) as promoters was synthesized and high-pressure F–T reaction (3 MPa) was carried out in the aim of accelerating the Co2C formation and tuning the interfaces of Co–Co2C. XRD, (HR)TEM, ICP, XPS and XAFS were conducted to study the relationship between the variations of Co–Co2C interfaces and HAs production. With the increasing Na contents, the ratios of Co to Co2C decreased as revealed by XAFS and the selectivity of HAs was decreasing. The fitting results from EXAFS revealed that the ratio of Co to Co2C is in direct proportion to the selectivity of HAs. This work provides a theoretical guidance to tune the interfaces of Co–Co2C and improve the HAs production in F–T reaction.

Precise control of selectivity in hydrogenation reactions is a long-standing challenge. Surface decoration of nanocatalysts with transition-metal oxide nanoparticles (NPs) is an effective strategy ...

The development of function-integrated catalysts to enable scalable and efficient biomass valorization is an important topic. Here, a stepwise methodology was developed to fabricate novel supported Au–Pd bimetallic catalysts featuring immobilized well-defined on-surface nanoarchitectures (Pd∧Au). This was achieved by an atomic decoration of a trace amount of Pd (Pd/Au molar ratio of 0.01–0.02) on the surface of 2 nm Au nanoparticle (NP, 0.86 wt %) preanchored to titania. Benefiting from their unique structural merits and the cooperative interplay among the selective hydrogenation activity furnished by the ultrasmall Pd∧Au NPs and prominent Lewis acidity endowed by TiO2, Pd0.02∧Au/TiO2 exhibits excellent activity with 100% conversion and over 90% selectivity and stability (turnover number up to 48 300) toward controlled ring-opening conversion of 5-hydroxymethylfurfural and related furanic compounds to the corresponding di- and triketone-type products under mild conditions (120 °C, 10 bar of H2). The resul...

Isolated cobalt single atoms with a high loading of 5.9 wt% are generated through an in situ preparation strategy., Single-atom catalysts (SACs) have shown great potential in a wide variety of chemical reactions and become the most active new frontier in catalysis due to the maximum efficiency of metal atom use. The key obstacle in preparing SAs lies in the development of appropriate supports that can avoid aggregation or sintering during synthetic procedures. As such, achieving high loadings of isolated SAs is nontrivial and challenging. Conventional methods usually afford the formation of SAs with extremely low loadings (less than 1.5 wt%). In this work, a new in situ preparation strategy that enables the synthesis of isolated cobalt (Co) SAs with an exceptionally high metal loading, up to 5.9 wt%, is developed. The approach is based on a simple one-step pyrolysis of a nitrogen-enriched molecular carbon precursor (1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile) and CoCl2. Furthermore, due to the successful electron transfer from carbon nitride to the isolated Co SAs, we demonstrate a high-performance photocatalytic H2 production using Co SAs as a co-catalyst, and the evolution rate is measured to be 1180 μmol g–1 h–1. We anticipate that this new study will inspire the discovery of more isolated SACs with high metal loadings, evidently advancing the development of this emerging type of advanced catalysts.

Uniform Pt quantum dots-decorated porous g-C3N4 nanosheets (Pt/CN) are fabricated by a facile impregnation-ultrasonic-calcination method, using melamine as precursor. The as-prepared samples are evidently investigated by X-ray diffraction, UV–vis diffuse reflection spectra, N2 adsorption, transmission electron microscope, surface photovoltage spectroscopy and photoluminescence. The deposited Pt quantum dots with particle size of ∼5 nm are decorated on the surface of porous g-C3N4 nanosheets uniformly. The Pt/CN nanosheets show conspicuous solar-driven photocatalytic activity for splitting water to produce H2. The solar-driven photocatalytic hydrogen production rate of Pt/CN is up to ∼107 μmol h−1 g−1, which is about 5 times higher than that of pristine g-C3N4. The enhancement can be attributed to the porous structure offering adequate surface active sites and the efficient decoration of uniform Pt quantum dots on g-C3N4 nanosheets facilitating the separation of photogenerated electron-hole pairs, which is confirmed by surface photovoltage spectroscopy and photoluminescence. The strategy for fabricating Pt quantum dots-decorated g-C3N4 nanosheets offers new insights for constructing other high-performance quantum dot-semiconductor photocatalytic materials.

The electrochemical reduction reaction of carbon dioxide (CO2RR) to carbon monoxide (CO) is the basis for the further synthesis of more complex carbon-based fuels or attractive feedstock. Single-atom catalysts have unique electronic and geometric structures with respect to their bulk counterparts, thus exhibiting unexpected catalytic activities. A nitrogen-anchored Zn single-atom catalyst is presented for CO formation from CO2RR with high catalytic activity (onset overpotential down to 24 mV), high selectivity (Faradaic efficiency for CO (FECO ) up to 95 % at -0.43 V), remarkable durability (>75 h without decay of FECO ), and large turnover frequency (TOF, up to 9969 h-1 ). Further experimental and DFT results indicate that the four-nitrogen-anchored Zn single atom (Zn-N4 ) is the main active site for CO2RR with low free energy barrier for the formation of *COOH as the rate-limiting step.

Hydrazine-assisted hydrogen evolution cell has been regarded as a promising route to replace conventional water splitting because of the lower thermodynamic oxidation potential. Therefore, the design and synthesis of highly efficient bifunctional electrocatalysts for anodic hydrazine oxidation reaction (HzOR) and cathodic hydrogen evolution reaction (HER) are crucial and highly desired. In this work, we report a facile synthesis strategy to prepare hollow CoSe2/MoSe2 nanospheres with abundant active interfaces for hydrazine-assisted hydrogen production. The homogeneous mixing of Co and Mo ions in the metal organic framework precursors ensures the formation of intimately contacted interfaces after selenization, leading to the “reinforced concrete” CoSe2/MoSe2 composites. Benefiting from the CoSe2/MoSe2 interfaces, the hollow CoSe2/MoSe2 nanosphere performs a low HER overpotential of 168 mV with an excellent stability over 12 h. Additionally, it also exhibits a low overpotential of 386 mV (vs. RHE) for HzOR and an ultralow cell voltage (1 mA cm−2) of 160 mV, which are among the best reported performance of powdered electrocatalysts. The present work develops a promising bifunctional electrocatalyst with active interfaces for energy-saving electrolytic hydrogen production.

The electrochemical reduction reaction of carbon dioxide (CO2RR) to carbon monoxide (CO) is the basis for the further synthesis of more complex carbon-based fuels or attractive feedstock. Single-atom catalysts have unique electronic and geometric structures with respect to their bulk counterparts, thus exhibiting unexpected catalytic activities. A nitrogen-anchored Zn single-atom catalyst is presented for CO formation from CO2RR with high catalytic activity (onset overpotential down to 24 mV), high selectivity (Faradaic efficiency for CO (FE