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

Advances in the development of novel cobalt Fischer-Tropsch catalysts for synthesis of long-chain hydrocarbons and clean fuels.

Atomically dispersed noble metal catalysts often exhibit high catalytic performances, but the metal loading density must be kept low (usually below 0.5%) to avoid the formation of metal nanoparticles through sintering. We report a photochemical strategy to fabricate a stable atomically dispersed palladium-titanium oxide catalyst (Pd1/TiO2) on ethylene glycolate (EG)-stabilized ultrathin TiO2 nanosheets containing Pd up to 1.5%. The Pd1/TiO2 catalyst exhibited high catalytic activity in hydrogenation of C=C bonds, exceeding that of surface Pd atoms on commercial Pd catalysts by a factor of 9. No decay in the activity was observed for 20 cycles. More important, the Pd1/TiO2-EG system could activate H2 in a heterolytic pathway, leading to a catalytic enhancement in hydrogenation of aldehydes by a factor of more than 55.

/pdf/photochemical-route-for-synthesizing-atomically-dispersed-1yjhc201ew.pdf

Photochemical route for synthesizing atomically dispersed palladium catalysts

Synthesis and catalytic properties of metal nanoparticles: Size, shape, support, composition, and oxidation state effects

The editors have assembled a world-class group of contributors who address the questions the combustion diagnostic community faces. They are chemists who identify the species to be measured and the interfering substances that may be present; physicists, who push the limits of laser spectroscopy and laser devices and who conceive suitable measuremen

Applied Combustion Diagnostics

Adsorption of CO on nanosize Pd particles was studied theoretically by density functional method and spectroscopically by means of infrared reflection absorption spectroscopy (IRAS) and sum frequency generation (SFG). A density functional approach was applied to three-dimensional crystallites of about 140 atoms. The model clusters were chosen as octahedral fragments of the face centered cubic (fcc) bulk, exhibiting (111) and (001) facets. Bare and adsorbate-decorated cluster models were calculated with Oh symmetry constraints. Various types of adsorption sites were inspected:  3-fold hollow, bridge, and on-top positions at (111) facets; 4-fold hollow and on-top sites at (001) facets; bridge positions at cluster edges; on-top positions at cluster corners; and on single Pd atoms deposited at regular (111) facets. Adsorption properties of the relatively small regular cluster facets (111) and (001) are calculated similar to those of corresponding ideal (infinite) Pd surfaces. However, the strongest CO bonding...

/pdf/co-adsorption-on-pd-nanoparticles-density-functional-and-4f6imeh83w.pdf

CO Adsorption on Pd Nanoparticles: Density Functional and Vibrational Spectroscopy Studies

http://w0.rz-berlin.mpg.de/hjfdb/pdf/321e.pdf

Sum frequency generation vibrational spectroscopy at solid–gas interfaces: CO adsorption on Pd model catalysts at ambient pressure

High-pressure CO adsorption on Pd(111) was examined by X-ray photoelectron spectroscopy (XPS) and vibrational sum frequency generation (SFG) from 200 to 400 K, and in a pressure range from 10-6 to 1 mbar. Even in the millibar regime both methods indicated that CO adsorbed in “regular” adsorption sites such as hollow, bridge, and on-top. By combination of XPS and SFG, a quantitative analysis of CO coverages at various pressures was performed. At high pressure, no CO structures different from those known from UHV studies were observed. Also, no indications of CO dissociation or carbonyl formation were found under the given experimental conditions, provided that the CO gas was sufficiently cleaned.

/pdf/high-pressure-studies-of-co-adsorption-on-pd-111-by-x-ray-2vhp9edy0i.pdf

High-Pressure Studies of CO Adsorption on Pd(111) by X-ray Photoelectron Spectroscopy and Sum-Frequency Generation

http://w0.rz-berlin.mpg.de/hjfdb/pdf/370e.pdf

Holger Unterhalt

Papers

CO Adsorption on Pd Nanoparticles: Density Functional and Vibrational Spectroscopy Studies

Sum frequency generation vibrational spectroscopy at solid–gas interfaces: CO adsorption on Pd model catalysts at ambient pressure

High-Pressure Studies of CO Adsorption on Pd(111) by X-ray Photoelectron Spectroscopy and Sum-Frequency Generation

C–O bond scission on "defect-rich and perfect" Pd(111)?

CO dissociation and CO hydrogenation on smooth and ion-bombarded Pd(111): SFG and XPS spectroscopy at mbar pressures