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.

Formaldehyde (HCHO) and carbon monoxide (CO) are both common air pollutants and hazardous to human body. It is imperative to develop the catalyst that is able to efficiently remove these pollutants. In this work, we activated Pt-MnO2 under different conditions for highly active oxidation of HCHO and CO, and the catalyst activated under CO displayed superior performance. A suite of complementary characterizations revealed that the catalyst activated with CO created the highly dispersed Pt nanoparticles to maintain a more positively charged state of Pt, which appropriately weakens the Mn-O bonding strength in the adjacent region of Pt for efficient supply of active oxygen during the reaction. Compared with other catalysts activated under different conditions, the CO-activated Pt-MnO2 displays much higher activity for oxidation of HCHO and CO. This research contributes to elucidating the mechanism for regulating the oxidation activity of Pt-based catalyst. 

Enhancing oxidation reaction over Pt-MnO2 catalyst by activation of surface oxygen

Mineralization of benzene, toluene, and xylene (BTX) with high efficiency at room temperature is still a challenge for the purification of indoor air. In this work, a foam Ti/Sb-SnO 2 /β-PbO 2 anode catalyst was prepared for electrocatalytically oxidizing gaseous toluene in an all-solid cell at ambient temperature. The complex Ti/Sb-SnO 2 /β-PbO 2 anode, which was prepared by sequentially deposing Sb-SnO 2 and β-PbO 2 on a foam Ti substrate, shows high electrocatalytic oxidation efficiency of toluene (80%) at 7 hr of reaction and high CO 2 selectivity (94.9%) under an optimized condition, i.e., a cell voltage of 2.0 V, relative humidity of 60% and a flow rate of 100 mL/min. The better catalytic performance can be ascribed to the high production rate of ⋅OH radicals from discharging adsorbed water and the inhibition of oxygen evolution on the surface of foam Ti/Sb-SnO 2 /β-PbO 2 anode when compared with the foam Ti/Sb-SnO 2 anode. Our results demonstrate that prepared complex electrodes can be potentially used for electrocatalytic removal of gaseous toluene at room temperature with a good performance. 

Electrocatalytic oxidation of gaseous toluene in an all-solid cell using a foam Ti/Sb-SnO2/β-PbO2 anode

Ce—Ti mixed oxide catalysts are prepared by precipitation from aqueous solutions of Ce(NO3)3 and Ti(SO4)2 with molar Ce/Ti ratios of 0.1, 0.2, 0.5, and 1.0 using excessive aqueous solution of urea (90 °C, 8 h), followed by calcination of the precipitate at 400, 500, or 600 °C for 5 h in air.

The Remarkable Improvement of a Ce—Ti Based Catalyst for NOx Abatement, Prepared by a Homogeneous Precipitation Method.

The miscellaneous volatile organic compounds (VOCs) in industrial flue gas streams usually demonstrate significant mutual inhibition effects, and the behavior of a particular VOC in mixtures is not clear, which hinders the application of catalytic technology. This study examines the catalytic oxidation and mixing effects of representative VOCs in industrial exhausts, consisting of acetone (AC), ethyl acetate (EA), and toluene (Tol), on common Mn-based catalysts (e.g., MnO2, Mn2O3, LaMnO3, and Mn3O4) by means of intrinsic activity evaluation, coadsorption, VOC temperature-programmed oxidation, in situ diffuse reflectance infrared Fourier transform spectroscopy, and gas chromatography-mass spectrometry. The results showed no inhibiting effect on the conversion of these VOCs when combusted together; instead, a significant mutual promotion effect was found, especially on Tol destruction, with a sharp decrease in the Tol T50 from 214 to 158 °C on MnO2. It is proposed for the first time that the addition of AC/EA in Tol combustion leads to the generation of o/m-methyl phenol, which changes the rate-determining step of the ring-opening process, thus elevating the conversion of Tol together with AC and EA in the mixture at low temperatures.

Synergistic Catalytic Oxidation of Typical Volatile Organic Compound Mixtures on Mn-Based Catalysts: Significant Promotion Effect and Reaction Mechanism.

Catalysts comprising Ru supported on CeO2 with different morphologies have been widely investigated in various reactions, and the Ru/CeO2-nanorod catalysts have generally demonstrated higher performance. The strong interaction between Ru and CeO2 nanorods, which is beneficial to oxygen activation, is usually considered to be responsible for the higher oxidation activity of the Ru/CeO2 nanostructures. However, how the metal–support interaction of Ru/CeO2 affects the activation of oxygen species still remains elusive. In this work, we prepared two nanostructures consisting of Ru supported on CeO2 nanorod (NR) and nanocube (NC), and the Ru/CeO2-NR catalyst exhibited higher catalytic activity than Ru/CeO2-NC in the oxidation of formaldehyde (HCHO) and carbon monoxide (CO) at low temperatures. The results of complementary characterization techniques revealed that the interaction between Ru and CeO2-NC is actually stronger than that of Ru/CeO2-NR, and more interestingly, we observed that the different Ru–CeO2 interactions induce distinct active oxygen species responsible for the oxidation reactions over Ru/CeO2-NR and Ru/CeO2-NC. The stronger interaction between Ru and CeO2-NC leads to the activation of lattice oxygen on CeO2-NC and a weakened redox capacity of RuOx species. In contrast, the moderate interaction between Ru and CeO2-NR induces a higher redox capacity of RuOx species but weak activation of lattice oxygen on CeO2-NR. The active RuOx on Ru/CeO2-NR is identified as being responsible for the high activity for HCHO/CO oxidation, while the activated lattice O of CeO2-NC in the Ru–CeO2 interfacial domain is the active species on Ru/CeO2-NC, rather than RuOx, resulting in low activity. These findings on Ru/CeO2 nanostructures provide insight into understanding the metal–support interaction over Ru/CeO2 catalysts. 

Changbin Zhang

Papers

Enhancing oxidation reaction over Pt-MnO2 catalyst by activation of surface oxygen

Electrocatalytic oxidation of gaseous toluene in an all-solid cell using a foam Ti/Sb-SnO2/β-PbO2 anode

The Remarkable Improvement of a Ce—Ti Based Catalyst for NOx Abatement, Prepared by a Homogeneous Precipitation Method.

Synergistic Catalytic Oxidation of Typical Volatile Organic Compound Mixtures on Mn-Based Catalysts: Significant Promotion Effect and Reaction Mechanism.

Effects of the Metal–Support Interaction in Ru/CeO2 Nanostructures on Active Oxygen Species for HCHO/CO Oxidation