Self-Reconstructed Amorphous CoO/NiCoB Heterostructure Catalysts for Enhanced HER Performance.

Amorphous electrocatalysts exhibit potentials as precursors for triggering the in situ reconstruction to generate the real catalytic active species toward electrochemical processes. In this work, a new kind of amorphous Ni-Co-B alloy pre-catalysts for hydrogen evolution reaction (HER) is reported, which is obtained via a facile electroless plating strategy on the nickel foam (NF). Interestingly, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and morphological characterizations identify the in situ reconstruction process during HER accompanied by the preferential leaching of surface B species and the formation of amorphous CoO nanosheet arrays as the real active sites.

Electrostatic Self-Assembly Synthesis of Pd/InO Nanocatalysts with Improved Performance Toward CO Hydrogenation to Methanol.

CO hydrogenation to methanol has emerged as a promising strategy for achieving carbon neutrality and mitigating global warming, in which the supported Pd/InO catalysts are attracting great attention due to their high selectivity. Nonetheless, conventional impregnation methods induce strong metal-support interaction (SMSI) between Pd and InO, which leads to the excessive reduction of InO and the formation of undesirable PdIn alloy in hydrogen-rich atmospheres. Herein, we innovatively synthesized Pd/InO nanocatalysts by the electrostatic self-assembly process between surface-modified composite precursors with opposite charges.

Toward -Alkane Hydroisomerization Reactions: High-Performance Pt-AlO/SAPO-11 Single-Atom Catalysts with Nanoscale Separated Metal-Acid Centers and Ultralow Platinum Content.

Long-chain -alkane hydroisomerization reaction plays a vital role in petrochemical and coal chemical industries, which could produce high-quality hydrocarbon fuels and lubricant base oils for modern transportation and mechanical drive. However, minimizing precious metal usage while maintaining the catalyst performance remains a great challenge. Herein, a novel bifunctional catalyst toward -alkane hydroisomerization reactions, Pt-AlO/SAPO-11 (Pt-A/S11) featuring nanoscale separated metal-acid active centers has been synthesized via a simple two-step procedure.

Bi-Sn Oxides for Highly Selective CO Electroreduction to Formate in a Wide Potential Window.

The electroreduction of CO into the highly value-added fuel formic acid (HCOOH) has been considered an ideal approach to convert renewable energy and mitigate environmental crisis. SnO electrode is one of the promising candidates to electrocatalytically convert CO to HCOOH, but its poor stability limits its future development and application. In this study, highly stable SnO /Bi O oxide catalysts are obtained by distributing SnO nanoparticles on the surface of Bi O sheets.

Highly Efficient and Selective CO Electro-Reduction to HCOOH on Sn Particle-Decorated Polymeric Carbon Nitride.

Electrochemical conversion of CO into liquid fuels by efficient and earth-abundant catalysts is of broad interest but remains a great challenge in renewable energy production and environmental remediation. Herein, a Sn particle-decorated polymeric carbon nitride (CN) electrocatalyst was successfully developed for efficient, durable, and highly selective CO reduction to formic acid. High-resolution X-ray photoelectron spectroscopy confirmed that the metallic Sn particles and CN matrix are bound by strong chemical interaction, rendering the composite catalyst a stable structure.

A large-surface-area TS-1 nanocatalyst: a combination of nanoscale particle sizes and hierarchical micro/mesoporous structures.

By a simple sequent process of dry-gel steam-assisted crystallization and following a top-down alkali-etching treatment, hierarchically structured TS-1 nanozeolites (nanoTS-1_D) with abundant micro/mesopores have been synthesized for the first time, and they exhibit remarkably high specific surface area of 606 m g and pore volume of 0.86 cm g. Characterization by XRD, FTIR, UV-vis and EM confirm the exclusive incorporation of titanium species in zeolite frameworks.

CuO/Co(OH) Nanosheets: A Novel Kind of Electrocatalyst for Highly Efficient Electrochemical Oxidation of Methanol.

With the booming of non-noble-metal electrocatalysts for efficient oxygen reduction reaction under alkaline conditions, corresponding anodic catalysts for methanol oxidation are urgently needed especially for direct methanol fuel cells with alkaline membranes. Here, we report the facile synthesis of a CuO/Co(OH)-nanosheet composite as a novel kind of high-performance electrochemical methanol oxidation reaction (MOR) catalyst. The obtained material with an optimized Cu/Co ratio shows much enhanced mass activity and area-specific activity, as well as excellent stability.

Metal-Organic Framework Nanosheet Electrocatalysts for Efficient H Production from Methanol Solution: Methanol-Assisted Water Splitting or Methanol Reforming?

Hydrogen (H) is presently one of the most promising clean and renewable energy sources, but the conventional hydrogen production by electrochemical water-splitting, though of great potential and extensively studied, is seriously obstructed especially by the anodic oxygen evolution reaction because of its sluggish kinetics. Herein, we report the efficient hydrogen production from methanol solution using facile-synthesized ultrathin 2D bi-metal-organic framework nanosheets (UMOFNs) as a precious metal-free anodic catalyst. The prepared UMOFNs showed a much lowered anodic potential of 1.

Fabrication of a mesoporous BaSrCoFeO perovskite as a low-cost and efficient catalyst for oxygen reduction.

A precious metal-free cathode catalyst, mesoporous BaSrCoFeO (m-BSCF), with a well crystallized perovskite framework and a porous structure (pore size of ∼10 nm) has been synthesized by a one-step co-nanocasting method. The obtained mesoporous perovskite m-BSCF demonstrated a much higher oxygen reduction reaction catalytic activity than its macroporous (CS-BSCF of ∼5 μm pore size) and nonporous counterparts (SG-BSCF). The mesoporous structure and oxygen vacancies endowed the obtained perovskite oxide m-BSCF with an approximate 4e pathway for the ORR comparable to the benchmark 20 wt% Pt/C and a stable electro-catalytic activity with 91% current density being retained after 5000 cycles, and excellent methanol tolerance.

Sodium carbonate-assisted synthesis of hierarchically porous single-crystalline nanosized zeolites.

Hierarchically porous single-crystalline nanosized zeolites as heterogeneous catalysts show great potential in fine chemistry because they offer more rich hierarchically porous channels for the mass transfer and molecular diffusion. However, the synthesis of hierarchically porous nanosized zeolites generally requires the assistance of templates acting as the mesoporogens, which limits its popularity. Herein, we report a one-pot and template-free synthesis of hierarchically porous single-crystalline nanosized zeolite beta only by introducing sodium carbonate in precursor solution.

On the Mesoporogen-Free Synthesis of Single-Crystalline Hierarchically Structured ZSM-5 Zeolites in a Quasi-Solid-State System.

Hierarchically structured zeolites (HSZs) have gained much academic and industrial interest owing to their multiscale pore structures and consequent excellent performances in varied chemical processes. Although a number of synthetic strategies have been developed in recent years, the scalable production of HSZs single crystals with penetrating and three-dimensionally (3-D) interconnected mesopore systems but without using a mesoscale template is still a great challenge. Herein, based on a steam-assisted crystallization (SAC) method, we report a facile and scalable strategy for the synthesis of single-crystalline ZSM-5 HSZs by using only a small amount of micropore-structure-directing agents (i.

Manganese Oxide Nanorod-Decorated Mesoporous ZSM-5 Composite as a Precious-Metal-Free Electrode Catalyst for Oxygen Reduction.

A precious-metal-free cathode catalyst, MnO2 nanorod-decorated mesoporous ZSM-5 zeolite nanocomposite (MnO2 / m-ZSM-5), has been successfully synthesized by a hydrothermal and electrostatic interaction approach for efficient electrochemical catalysis of the oxygen reduction reaction (ORR). The active MnOOH species, that is, Mn(4+) /Mn(3+) redox couple and Brønsted acid sites on the mesoporous ZSM-5 matrix facilitate an approximately 4 e(-) process for the catalysis of the ORR comparable to commercial 20 wt % Pt/C. Stable electrocatalytic activity with 90 % current retention after 5000 cycles, and more importantly, excellent methanol tolerance is observed.

Mesoporogen-Free Synthesis of Hierarchically Structured Zeolites with Variable Si/Al Ratios via a Steam-Assisted Crystallization Process.

In the absence of additional mesoporous template, hierarchically structured zeolites (HSZs) with variable Si/Al ratios (30-150) have been successfully synthesized via a newly developed steam-assisted crystallization process. The synthesized materials were characterized with powder X-ray diffraction, nitrogen sorption measurement, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma optical emission spectrometry, solid-state nuclear magnetic resonance, and ammonia temperature-programmed desorption. All these results prove that the synthesized materials feature high crystallinity (microporous framework) and auxiliary mesoporous structure.

Mesostructured amorphous manganese oxides: facile synthesis and highly durable elimination of low-concentration NO at room temperature in air.

At a high space velocity of 120 000 mL g(-1) h(-1) and a relative humidity of 50-90%, 98% removal of 10 ppm NO has been achieved for over 237 h and no sign of deactivation was observed with mesostructured amorphous manganese oxides (AMO), due to the prevention of the catalyst active sites from deactivation.

One-step hydrothermal synthesis of nitrogen-doped carbon nanotubes as an efficient electrocatalyst for oxygen reduction reactions.

A high amount of heteroatom doping in carbon, although favorable for enhanced density of catalytically active sites, may lead to substantially decreased electroconductivity, which is necessary for the electrochemical oxygen reduction reaction. Herein, a relatively low amount of nitrogen was successfully doped into carbon nanotubes (CNTs) by a hydrothermal approach in one step, and the synthesized nitrogen-doped CNT (CNT-N) materials retained most of the original, excellent characteristics, such as the graphitic structure, tubular morphology, and high surface area, of CNTs. The resultant CNT-N materials, although containing a relatively low amount of nitrogen doping, exhibited high electrocatalytic ORR activity, comparable to that of 20 wt% Pt/C; long durability; and, more importantly, largely inhibited methanol crossover effect.

One-step synthesis of sulfur doped graphene foam for oxygen reduction reactions.

Sulfur doped graphene foam has been successfully synthesized by a simple solve-thermal method, which exhibited a much enhanced oxygen reduction reaction (ORR) catalytic activity as well as an especially high electrochemical stability, and would be a promising non-metal cathode catalyst for the ORR.

Mesostructured platinum-free anode and carbon-free cathode catalysts for durable proton exchange membrane fuel cells.

As one of the most important clean energy sources, proton exchange membrane fuel cells (PEMFCs) have been a topic of extensive research focus for decades. Unfortunately, several critical technique obstacles, such as the high cost of platinum electrode catalysts, performance degradation due to the CO poisoning of the platinum anode, and carbon corrosion by oxygen in the cathode, have greatly impeded its commercial development. A prototype of a single PEMFC catalyzed by a mesostructured platinum-free WO3/C anode and a mesostructured carbon-free Pt/WC cathode catalysts is reported herein.

KF-loaded mesoporous Mg-Fe bi-metal oxides: high performance transesterification catalysts for biodiesel production.

Using newly developed mesoporous Mg-Fe bi-metal oxides as supports, a novel kind of high performance transesterification catalysts for biodiesel production has been synthesized. More importantly, the impregnation solvent was for the first time found to substantially affect the structures and catalytic performances of the resultant transesterification catalysts.

Colloidal HPMO nanoparticles: silica-etching chemistry tailoring, topological transformation, and nano-biomedical applications.

Hybridization produces the better: Colloidal hollow periodic mesoporous organosilica nanoparticles (HPMO NPs) with tunable compositions and highly hybridized nanostructures are successfully synthesized by a simple, easily scale-up but versatile silica-etching chemistry (alkaline or HF etching) for their applications in nano-fabrication and nano-medicine.

An in situ carbonization-replication method to synthesize mesostructured WO3/C composite as nonprecious-metal anode catalyst in PEMFC.

A meostructured WO(3)/C composite with crystalline framework and high electric conductivity has been synthesized by a new in situ carbonization-replication route using the block copolymer (poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)) present in situ in the pore channels of mesoporous silica template as carbon source. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, thermogravimetry differential thermal analysis, and N(2) adsorption techniques were adopted for the structural characterization. Cyclic voltammetry, chronoamperometry, and single-cell test for hydrogen electrochemical oxidation were adopted to characterize the electrochemical activities of the mesoporous WO(3)/C composite.

An in situ carbonaceous mesoporous template for the synthesis of hierarchical ZSM-5 zeolites by one-pot steam-assisted crystallization.

Blackened catalyst: Zeolites with large external surface area and mesopore volume were synthesized by a one-pot templating strategy, in which the crystallization proceeded concurrently with in situ carbonization templating to produce a mesoporous structure. The hierarchical materials exhibited superior catalytic performance over conventional zeolites in Friedel-Crafts acylation of anisole.

Hierarchical mesoporous zeolites: direct self-assembly synthesis in a conventional surfactant solution by kinetic control over the zeolite seed formation.

By kinetic control over the zeolite seed formation, we report the direct fabrication of hierarchical mesoporous zeolites using hexadecyl trimethyl ammonium bromide (CTAB) as the soft template in a conventional solution route. Nanometer-sized, subnanocrystal-type zeolite seeds with a high degree of polymerization are essential to prevent the formation of a separate amorphous mesoporous phase and the phase separation between the mesophase and zeolite crystals in the presence of CTAB and a certain amount of ethanol. The mechanisms for the formation of hierarchically porous zeolites in the solution process, including the effect of mother liquid aging, formation of subnanocrystal zeolite seeds and their self-assembly effect with CTAB, and the role of ethanol are proposed and discussed in detail.

Hollow mesoporous zeolite microspheres: hierarchical macro-/meso-/microporous structure and exceptionally enhanced adsorption properties.

We report the synthesis of a new kind of uniform hollow zeolite microspheres with hierarchical macro-/meso-/microporosity by an efficient strategy combining bi-templating, steam-assisted crystallization and then a mild alkaline etching method. This novel product has a hollow architecture, highly crystallized zeolite shells and more importantly, high dye adsorption capabilities.

Superparamagnetic mesoporous Mg-Fe bi-metal oxides as efficient magnetic solid-base catalysts for Knoevenagel condensations.

Superparamagnetic mesoporous Mg-Fe bi-metal oxides with varied Mg-Fe atomic ratios have been successfully synthesized as solid base catalysts. The M2F-400 catalyst with Mg/Fe atomic ratio = 2 showed extraordinarily high activities for Knoevenagel reactions even at room temperature. It could be magnetically separated, recycled, and reused for at least five cycles.

Hierarchical mesoporous TS-1 zeolite: a highly active and extraordinarily stable catalyst for the selective oxidation of 2,3,6-trimethylphenol.

We report the synthesis of a new hierarchical mesoporous TS-1 type zeolite by a simple steam-assisted crystallization method. This novel product exhibits high catalytic activity and a strongly prolonged lifetime in the selective oxidation of 2,3,6-trimethylphenol to trimethyl-p-benzoquinone.