Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Supported metal nanostructures are the most widely used type of heterogeneous catalyst in industrial processes. The size of metal particles is a key factor in determining the performance of such catalysts. In particular, because low-coordinated metal atoms often function as the catalytically active sites, the specific activity per metal atom usually increases with decreasing size of the metal particles. However, the surface free energy of metals increases significantly with decreasing particle size, promoting aggregation of small clusters. Using an appropriate support material that strongly interacts with the metal species prevents this aggregation, creating stable, finely dispersed metal clusters with a high catalytic activity, an approach industry has used for a long time. Nevertheless, practical supported metal catalysts are inhomogeneous and usually consist of a mixture of sizes from nanoparticles to subnanometer clusters. Such heterogeneity not only reduces the metal atom efficiency but also frequent...

Single-atom catalysts: a new frontier in heterogeneous catalysis.

Hollow micro-/nanostructures are of great interest in many current and emerging areas of technology. Perhaps the best-known example of the former is the use of fly-ash hollow particles generated from coal power plants as partial replacement for Portland cement, to produce concrete with enhanced strength and durability. This review is devoted to the progress made in the last decade in synthesis and applications of hollow micro-/nanostructures. We present a comprehensive overview of synthetic strategies for hollow structures. These strategies are broadly categorized into four themes, which include well-established approaches, such as conventional hard-templating and soft-templating methods, as well as newly emerging methods based on sacrificial templating and template-free synthesis. Success in each has inspired multiple variations that continue to drive the rapid evolution of the field. The Review therefore focuses on the fundamentals of each process, pointing out advantages and disadvantages where appropriate. Strategies for generating more complex hollow structures, such as rattle-type and nonspherical hollow structures, are also discussed. Applications of hollow structures in lithium batteries, catalysis and sensing, and biomedical applications are reviewed.

Hollow Micro-/Nanostructures: Synthesis and Applications**

As the field of nanomedicine emerges, there is a lag in research surrounding the topic of nanoparticle (NP) toxicity, particularly concerned with mechanisms of action. The continuous emergence of bacterial resistance has challenged the research community to develop novel antibiotic agents. Metal NPs are among the most promising of these because show strong antibacterial activity. This review summarizes and discusses proposed mechanisms of antibacterial action of different metal NPs. These mechanisms of bacterial killing include the production of reactive oxygen species, cation release, biomolecule damages, ATP depletion, and membrane interaction. Finally, a comprehensive analysis of the effects of NPs on the regulation of genes and proteins (transcriptomic and proteomic) profiles is discussed.

https://link.springer.com/content/pdf/10.1186/s12951-017-0308-z.pdf

Metal nanoparticles: understanding the mechanisms behind antibacterial activity.

It is well known that urbanization and industrialization have resulted in the rapidly increasing emissions of volatile organic compounds (VOCs), which are a major contributor to the formation of secondary pollutants (e.g., tropospheric ozone, PAN (peroxyacetyl nitrate), and secondary organic aerosols) and photochemical smog. The emission of these pollutants has led to a large decline in air quality in numerous regions around the world, which has ultimately led to concerns regarding their impact on human health and general well-being. Catalytic oxidation is regarded as one of the most promising strategies for VOC removal from industrial waste streams. This Review systematically documents the progresses and developments made in the understanding and design of heterogeneous catalysts for VOC oxidation over the past two decades. It addresses in detail how catalytic performance is often drastically affected by the pollutant sources and reaction conditions. It also highlights the primary routes for catalyst deactivation and discusses protocols for their subsequent reactivation. Kinetic models and proposed oxidation mechanisms for representative VOCs are also provided. Typical catalytic reactors and oxidizers for industrial VOC destruction are further discussed. We believe that this Review will provide a great foundation and reference point for future design and development in this field.

/pdf/recent-advances-in-the-catalytic-oxidation-of-volatile-zw2c35dbg7.pdf

Recent Advances in the Catalytic Oxidation of Volatile Organic Compounds: A Review Based on Pollutant Sorts and Sources.

While C–O bond cleavage is pivotal in the depolymerization/valorization of lignin, it is still challenging to control the reaction selectivity under high activity due to the higher dissociation energy of aromatic C–O bonds relative to other reactions such as direct ring hydrogenation. Herein, we report the activation of Al2O3-supported earth-abundant MnO with embedded Ru to enhance the selective hydrogenolysis of aromatic C–O bonds in both a model compound and real lignin. Complementary characterizations demonstrate that the embedment of Ru into the MnO phase generates vacancy-enriched MnO under a hydrogen atmosphere, and such abundant active sites enable about threefold enhancement of the specific reaction rate for C–O bond hydrogenolysis. Moreover, the defective MnO overlayer on Ru nanoparticles has a stronger interaction with the O in diphenyl ether with preferential vertical adsorption, which inhibits the activation and hydrogenation of the aromatic ring, leading to higher selectivity for direct C–O bond cleavage. In the depolymerization of real lignin, the bimetallic Ru–MnO shows significantly higher (fivefold) activity than monometallic Ru under the tested condition. This work provides a general framework for the rational design of highly efficient catalysts for selective C–O bond cleavage. 

Activating MnO with Embedded Ru for Enhanced Selective Hydrogenolysis of C–O Bonds in Lignin-Derived Ethers over Ru–MnO/Al2O3

While utilization of transitional metals as a promoter has been extensively studied to enhance the activity of Pt-based catalysts for the oxidation of formaldehyde (HCHO), there is still a lack of well elucidated property-function relationship for the rational selection of a promoter in catalyst design. Herein, we modified a Pt/CeO2 catalyst with two transitional metal dopants (i.e., Mn and Cu) that showed negligible influence on the physical structure of the Pt-CeO2 matrix but distinct effects on the activity of the catalyst. Complementary characterizations combined with density functional theory modeling revealed that the transitional metal dopants significantly modified the electronic structure of the catalyst and shifted the d-band of Pt to higher energy with different extents, which may tune the bonding strength of HCHO/intermediates with the Pt-CeO2 interface domain. The catalyst with moderate bonding strength (i.e., Pt-Mn/CeO2) displayed the highest reactivity under the ambient condition, while Pt-Cu/CeO2 with the highest bonding strength showed a dramatically decreased activity. No correlation was observed between the abundancy of the active oxygen and catalytic activity, likely due to the oxygen supply having a much higher rate than the rate-determining step. This work contributes to the elucidation about the property-function relationship of a transitional metal dopant in Pt-based catalysts for the oxidation of HCHO.

Electronic Modification by Transitional Metal Dopants to Tune the Oxidation Activity of Pt-CeO2-Based Catalysts.

Disclosed is a Ce-based composite oxide catalyst for selective catalytic reducing nitrogen oxides with ammonia, which comprises Ce oxide and at least one oxide of transition metal except Ce. The Ce-based composite oxide catalyst is prepared by a simple method which uses non-toxic and harmless raw materials, and it has the following advantages: high catalytic activity, and excellent selectivity for generating nitrogen etc. The catalyst can be applied in catalytic cleaning plant for nitrogen oxides from mobile and stationary sources.

Ce-BASED COMPOSITE OXIDE CATALYST, PREPARATION METHOD AND APPLICATION THEREOF

Long-term stable Zn metal anodes by electrodeposited manganese dioxide for aqueous rechargeable zinc ion batteries

Pd/Al2O3 was pretreated by CO, H2 and NaBH4 reduction, respectively. The reduced catalysts were tested for o-xylene oxidation and characterized by power X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and temperature-programmed decomposition of palladium hydride (TPDH). The characterizations indicate the pretreatments lead to distinct Pd particle sizes and amount of surface activated oxygen species, which are responsible for the catalytic performance. Compared with H2 and NaBH4 reduction methods, CO reduction shows a strong interaction between Pd and Al2O3 with smaller Pd particle size and more surface activated oxygen. It exhibited excellent catalytic performance, complete oxidation of 50 ppmV o-xylene at 85°C with a WHSV of 60,000 mL/(g∙hr). 

Changbin Zhang

Papers

Activating MnO with Embedded Ru for Enhanced Selective Hydrogenolysis of C–O Bonds in Lignin-Derived Ethers over Ru–MnO/Al2O3

Electronic Modification by Transitional Metal Dopants to Tune the Oxidation Activity of Pt-CeO2-Based Catalysts.

Ce-BASED COMPOSITE OXIDE CATALYST, PREPARATION METHOD AND APPLICATION THEREOF

Long-term stable Zn metal anodes by electrodeposited manganese dioxide for aqueous rechargeable zinc ion batteries

Effect of different reduction methods on Pd/Al2O3 for o-xylene oxidation at low temperature.