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.

Investigation into the Enhanced Catalytic Oxidation of o-Xylene over MOF-Derived Co3O4 with Different Shapes: The Role of Surface Twofold-Coordinate Lattice Oxygen (O2f)

The Ag/Al2O3 catalyst possesses high activity for selective catalytic oxidation of ammonia (NH3–SCO), and its activity could be significantly improved by H2 pretreatment. It is generally accepted that the enhancement of Ag/Al2O3 activity after H2 reduction is due to the promoted O2 activation by metallic Ag species. Here, we show that the recovery of Bronsted acid sites via H2 reduction is also an important factor. Ag/Al2O3 and H2-pretreated Ag/Al2O3 (Ag/Al2O3–H2) catalysts were prepared and tested for the NH3–SCO performances, and also carefully characterized. It is revealed that Ag species were anchored on the Al2O3 surface through exchange between Ag+ and H+ in AlOH groups during the preparation process, and therefore occupied the Bronsted acid sites of Al2O3. H2 reduction could break the Ag–O bonds and thus recover the Bronsted acid sites. In situ DRIFTS results show that NH4+ species adsorbed on Bronsted acid sites is much more active for reaction with O2 than NH3 species adsorbed on Lewis acid sites...

Insights into the Activation Effect of H2 Pretreatment on Ag/Al2O3 Catalyst for the Selective Oxidation of Ammonia

Photocatalytic oxidation of gaseous ammonia (NH3) at room temperature is an efficient method for the elimination of NH3 emitted from indoor and outdoor sources, such as decorative materials, intensive livestock farming, chemical processes, etc. Herein, we prepared the anatase TiO2 with clean dominant {001}, {101} and {010} facets, and tested their photocatalytic activity for NH3 oxidation. The test results show that the photocatalytic activity order for NH3 oxidation is revealed as {001} > {101} > {010}. The catalysts were characterized by XRD, FE-SEM, XPS, UV–vis, in situ DRIFTS and TPD methods. It is indicated that TiO2 with dominant {001} facets has the highest separation efficiency of the photogenerated charges among three catalysts. Since the photogenerated holes is responsible for initiating the first step of NH3 oxidation, the TiO2 with dominant {001} facets demonstrated the exceptional activity. In addition, the photocatalytic oxidation of NH3 possibly follow the photo-iSCR mechanism. The photogenerated electrons activate O2 and then participate in the formation of reactive intermediate NOx followed by the photo-NH3-iSCR to final products. The present study will improve our understanding about the performance of anatase TiO2 for photocatalytic oxidation of NH3.

Facet-dependent performance of anatase TiO2 for photocatalytic oxidation of gaseous ammonia

Ag/Al2O3 is a promising catalyst for the selective catalytic reduction (SCR) by hydrocarbons (HC) of NO
 x
 in both laboratory and diesel engine bench tests. New developments of the HC-SCR of NO
 x
 over a Ag/Al2O3 catalyst are reviewed, including the efficiencies and sulfur tolerances of different Ag/Al2O3-reductant systems for the SCR of NO
 x
 ; the low-temperature activity improvement of H2-assisted HC-SCR of NO
 x
 over Ag/Al2O3; and the application of a Ag/Al2O3-ethanol SCR system with a heavy-duty diesel engine. The discussions are focused on the reaction mechanisms of different Ag/Al2O3-reductant systems and H2-assisted HC-SCR of NO
 x
 over Ag/Al2O3. A SO2-resistant surface structure in situ synthesized on Ag/Al2O3 by using ethanol as a reductant is proposed based on the study of the sulfate formation. These results provide new insight into the design of a high-efficiency NO
 x
 reduction system. The diesel engine bench test results showed that a Ag/Al2O3-ethanol system is promising for catalytic cleaning of NO
 x
 in diesel exhaust.

Review of Ag/Al 2 O 3 -Reductant System in the Selective Catalytic Reduction of NO x

For human health and environmental protection, removal of formaldehyde (HCHO) has become a hot topic, and completely catalytic oxidation at room temperature has been identified as one of the efficient routes for solving this problem. Recently, it has been reported that zeolite-supported Pt catalysts are active for HCHO oxidation at low temperatures, but they are still unable to completely oxidize HCHO at room temperature. To enhance the activity, it has been suggested to increase the Pt dispersion and acidic density in the zeolite-supported Pt catalysts. We therefore chose Al-rich Beta as a zeolite support because abundant aluminum species in the zeolite framework are advantageous for increasing acidic density through ion-exchange of protons and for improving Pt metal dispersion through the metal-zeolite interaction by increasing the negative charge of the zeolite framework with positively charged metal ions. As we expected, the Al-rich Beta zeolite supported platinum catalyst is very active, giving complete oxidation of HCHO at room temperature. To the best of our knowledge, this is the first time the complete oxidation of HCHO at room temperature over a zeolite-supported noble metal catalyst has been realized. In addition to its extraordinary activity, this catalyst is also very stable and selective. The strategy of designing zeolite-supported noble metal catalysts might offer an alternative way to develop highly efficient heterogeneous catalysts for the removal of air pollutants.

Changbin Zhang

Papers

Investigation into the Enhanced Catalytic Oxidation of o-Xylene over MOF-Derived Co3O4 with Different Shapes: The Role of Surface Twofold-Coordinate Lattice Oxygen (O2f)

Insights into the Activation Effect of H2 Pretreatment on Ag/Al2O3 Catalyst for the Selective Oxidation of Ammonia

Facet-dependent performance of anatase TiO2 for photocatalytic oxidation of gaseous ammonia

Review of Ag/Al 2 O 3 -Reductant System in the Selective Catalytic Reduction of NO x

Complete oxidation of formaldehyde at room temperature over an Al-rich Beta zeolite supported platinum catalyst