Dynamic phase transitions dictate the size effect and activity of supported gold catalysts.

The landmark discovery of gold catalysts has aroused substantial interest in heterogeneous catalysis, yet the catalytic mechanism remains elusive. For carbon monoxide oxidation on gold nanoparticles (NPs) supported on ceria surfaces, it is widely believed that carbon monoxide adsorbs on the gold particles, while the reaction occurs at the gold/ceria interface. Here, we have investigated the dynamic changes of supported gold NPs with various sizes in a carbon monoxide oxidation atmosphere using deep potential molecular dynamics simulations.

A Highly Active Molybdenum Carbide Catalyst with Dynamic Carbon Flux for Reverse Water-Gas Shift Reaction.

Molybdenum carbide has been reported as an efficient and stable catalyst for reverse water-gas shift (RWGS) reaction. The conventional understanding of the mechanism suggests domination of the surface phenomena, with only surface or subsurface layers partaking in the catalytic cycle. In this study, we presented a highly active MoC catalyst from carburization process, which showed a mass-specific reaction rate over 260 μm with dynamic carbon flux in the bulk phase of the catalyst.

Ceria-based supported metal catalysts for the low-temperature water-gas shift reaction.

Water-gas shift (WGS) reaction is a crucial step for the industrial production of hydrogen or upgrading the hydrogen generated from fossil or biomass sources by removing the residual CO. However, current industrial catalysts for this process, comprising Cu/ZnO and FeO-CrO, suffer from safety or environmental issues. In the past decades, ceria-based materials have attracted wide attention as WGS catalysts due to their abundant oxygen vacancies and tunable metal-support interaction.

Single-Atom Barium Promoter Enormously Enhanced Non-Noble Metal Catalyst for Ammonia Decomposition.

As a well-established topic, single-atom catalyst has drawn growing interest for its high utilization of metal. However, researchers prefer to develop various active metals with single-atom form, the intrinsic roles of single-atom promoters are usually underrated, which are significant in boosting reaction activity. In this work, Ba single atoms were in situ prepared in the Co-Ba/YO catalyst with crystallized BaCO as the precursor under the ammonia decomposition reaction condition.

Direct cleavage of C=O double bond in CO by the subnano MoO surface on MoN.

Compared to H-assisted activation mode, the direct dissociation of CO into carbonyl (*CO) with a simplified reaction route is advantageous for CO-related synthetic processes and catalyst upgrading, while the stable C = O double bond makes it very challenging. Herein, we construct a subnano MoO layer on the surface of MoN, which provides a dynamically changing surface of MoO↔MoO (x < 3) for catalyzing CO hydrogenation. Rich oxygen vacancies on the subnano MoO surface with a high electron donating capacity served as a scissor to directly shear the C = O double bond of CO to form CO at a high rate.

Microstructure-Reconfigured Graphene Oxide Aerogel Metamaterials for Ultrarobust Directional Sensing at Human-Machine Interfaces.

Graphene aerogels hold huge promise for the development of high-performance pressure sensors for future human-machine interfaces due to their ordered microstructure and conductive network. However, their application is hindered by the limited strain sensing range caused by the intrinsic stiffness of the porous microstructure. Herein, an anisotropic cross-linked chitosan and reduced graphene oxide (CCS-rGO) aerogel metamaterial is realized by reconfiguring the microstructure from a honeycomb to a buckling structure at the dedicated cross-section plane.

Catalytic properties of trivalent rare-earth oxides with intrinsic surface oxygen vacancy.

Oxygen vacancy (O) is an anionic defect widely existed in metal oxide lattice, as exemplified by CeO, TiO, and ZnO. As O can modify the band structure of solid, it improves the physicochemical properties such as the semiconducting performance and catalytic behaviours. We report here a new type of O as an intrinsic part of a perfect crystalline surface.

MXene/Nitrogen-Doped Carbon Nanosheet Scaffold Electrode toward High-Performance Solid-State Zinc Ion Supercapacitor.

While MXene is widely used as an electrode material for supercapacitor, the intrinsic limitation of stacking caused by the interlayer van der Waals forces has yet to be overcome. In this work, a strategy is proposed to fabricate a composite scaffold electrode (MCN) by intercalating MXene with highly nitrogen-doped carbon nanosheets (CN). The 2D structured CN, thermally converted and pickling from Zn-hexamine (Zn-HMT), serves as a spacer that effectively prevents the stacking of MXene and contributes to a hierarchically scaffolded structure, which is conducive to ion movement; meanwhile, the high nitrogen-doping of CN tunes the electronic structure of MCN to facilitate charge transfer and providing additional pseudocapacitance.

Boosting reactivity of water-gas shift reaction by synergistic function over CeO/CoO/Co dual interfacial structures.

Dual-interfacial structure within catalysts is capable of mitigating the detrimentally completive adsorption during the catalysis process, but its construction strategy and mechanism understanding remain vastly lacking. Here, a highly active dual-interfaces of CeO/CoO/Co is constructed using the pronounced interfacial interaction from surrounding small CeO islets, which shows high activity in catalyzing the water-gas shift reaction. Kinetic evidence and in-situ characterization results revealed that CeO modulates the oxidized state of Co species and consequently generates the dual active CeO/CoO/Co interface during the WGS reaction.

Cascade NH Oxidation and NO Decomposition via Bifunctional Co and Cu Catalysts.

The selective catalytic oxidation of NH (NH-SCO) to N is an important reaction for the treatment of diesel engine exhaust. CoO has the highest activity among non-noble metals but suffers from NO release. Such NO emissions have recently been regulated due to having a 300× higher greenhouse gas effect than CO.

Promoting Molecular Exchange on Rare-Earth Oxycarbonate Surfaces to Catalyze the Water-Gas Shift Reaction.

It is highly desirable to fabricate an accessible catalyst surface that can efficiently activate reactants and desorb products to promote the local surface reaction equilibrium in heterogeneous catalysis. Herein, rare-earth oxycarbonates (LnOCO, where Ln = La and Sm), which have molecular-exchangeable (HO and CO) surface structures according to the ordered layered arrangement of LnO and CO ions, are unearthed. On this basis, a series of LnOCO-supported Cu catalysts are prepared through the deposition precipitation method, which provides excellent catalytic activity and stability for the water-gas shift (WGS) reaction.

Pt-O synergistic sites on MoO/γ-MoN heterostructure for low-temperature reverse water-gas shift reaction.

In heterogeneous catalysis, the interface between active metal and support plays a key role in catalyzing various reactions. Specially, the synergistic effect between active metals and oxygen vacancies on support can greatly promote catalytic efficiency. However, the construction of high-density metal-vacancy synergistic sites on catalyst surface is very challenging.

Catalytically efficient Ni-NiO-YO interface for medium temperature water-gas shift reaction.

The metal-support interfaces between metals and oxide supports have long been studied in catalytic applications, thanks to their significance in structural stability and efficient catalytic activity. The metal-rare earth oxide interface is particularly interesting because these early transition cations have high electrophilicity, and therefore good binding strength with Lewis basic molecules, such as HO. Based on this feature, here we design a highly efficient composite Ni-YO catalyst, which forms abundant active Ni-NiO-YO interfaces under the water-gas shift (WGS) reaction condition, achieving 140.

Partially sintered copper‒ceria as excellent catalyst for the high-temperature reverse water gas shift reaction.

For high-temperature catalytic reaction, it is of significant importance and challenge to construct stable active sites in catalysts. Herein, we report the construction of sufficient and stable copper clusters in the copper‒ceria catalyst with high Cu loading (15 wt.%) for the high-temperature reverse water gas shift (RWGS) reaction.

Heterostructured Ceria-Titania-Supported Platinum Catalysts for the Water Gas Shift Reaction.

The water gas shift (WGS) reaction is a key process in the industrial hydrogen production and the development and application of the proton exchange membrane fuel cell. Metal oxide-supported highly dispersed Pt has been proved as an efficient catalyst for the WGS reaction. In this work, a series of supported 0.

Generation of the Surface Oxygen Vacancies in a Copper-Ceria Catalyst for the Water-Gas Shift Reaction.

The dissociation of HO is a crucial aspect for the water-gas shift reaction, which often occurs on the vacancies of a reducible oxide support. However, the vacancies sometimes run off, thus inhibiting HO dissociation. After high-temperature treatment, the ceria supports were lacking vacancies because of sintering.

Unique structure of active platinum-bismuth site for oxidation of carbon monoxide.

As the technology development, the future advanced combustion engines must be designed to perform at a low temperature. Thus, it is a great challenge to synthesize high active and stable catalysts to resolve exhaust below 100 °C. Here, we report that bismuth as a dopant is added to form platinum-bismuth cluster on silica for CO oxidation.

Facile Fabrication of CeO-AlO Hollow Sphere with Atomically Dispersed Fe via Spray Pyrolysis.

A facile spray pyrolysis method is introduced to construct the hollow CeO-AlO spheres with atomically dispersed Fe. Only nitrates and ethanol were involved during the one-step preparation process using the ultrasound spray pyrolysis approach. Detailed explorations demonstrated that differences in the pyrolysis temperature of the precursors and heat transfer are crucial to the formation of the hollow nanostructure.

The Effect of Hydrogenated TiO to the Au/TiO Catalyst in Catalyzing CO Oxidation.

Supported Au catalysts are widely used for CO oxidation due to their extremely high activity, and the modification of a support structure is a crucial method to improve catalytic performance. Herein, we prepared gold catalysts supported on flaky TiO and on TiO hydrogenated at different temperatures (200, 400, and 600 °C). We found that the sample with the support pretreated in hydrogen at 600 °C (0.

Highly Efficient CuO/α-MnO Catalyst for Low-Temperature CO Oxidation.

Copper manganese composite (hopcalite) catalyst has been widely explored for low-temperature CO oxidation reactions. However, the previous reports on the stabilization of such composite catalysts have shown that they deactivated severely under moist conditions. Herein, we developed an α-MnO nanorod-supported copper oxide catalyst that is very active and stable for the conditions with or without moisture by the deposition precipitation (DP) method.

Intrinsically Active Surface in a Pt/γ-MoN Catalyst for the Water-Gas Shift Reaction: Molybdenum Nitride or Molybdenum Oxide?

Apart from active metals, supports also contribute significantly to the catalytic performance of supported metal catalysts. On account of the formed strain and defects, the heterostructured surface of the support may play a crucial role to activate the reactant molecules, while it is usually neglected. In this work, the Pt/γ-MoN catalyst was prepared via a facile solution method.

Use of fusion transcription factors to reprogram cellulase transcription and enable efficient cellulase production in .

Background: is widely used for cellulase production and accepted as an example for cellulase research. Cre1-mediated carbon catabolite repression (CCR) can significantly inhibit the transcription of cellulase genes during cellulase fermentation in . .

Construction of Active Site in a Sintered Copper-Ceria Nanorod Catalyst.

The construction of stable active site in nanocatalysts is of great importance but is a challenge in heterogeneous catalysis. Unexpectedly, coordination-unsaturated and atomically dispersed copper species were constructed and stabilized in a sintered copper-ceria catalyst through air-calcination at 800 °C. This sintered copper-ceria catalyst showed a very high activity for CO oxidation with a CO consumption rate of 6100 μmol·g·s at 120 °C, which was at least 20 times that of other reported copper catalysts.