David Lennon
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View article: The application of neutron imaging to examine ethene hydrogenation over a carbon-supported palladium catalyst
The application of neutron imaging to examine ethene hydrogenation over a carbon-supported palladium catalyst Open
The combination of a heterogeneous catalyst operating within a defined reactor comes within the domain of reaction engineering, which takes cognisance of combined roles for both the catalyst and the reactor to define the overall operationa…
View article: Phosgene synthesis catalysis: reaction kinetics and adsorption characteristics over Norit RX3 Extra activated carbon formulation
Phosgene synthesis catalysis: reaction kinetics and adsorption characteristics over Norit RX3 Extra activated carbon formulation Open
A commercial activated carbon (Norit RX3 Extra) is examined with respect to phosgene synthesis via rate law determination and non-competitive adsorption measurements. A proposed reaction model is validated through these measurements.
View article: The impact of co-feeding carbon dioxide in Fischer–Tropsch-to-olefin catalysis: an inelastic neutron scattering study
The impact of co-feeding carbon dioxide in Fischer–Tropsch-to-olefin catalysis: an inelastic neutron scattering study Open
An investigation into the addition of CO 2 to the feedstock for a Fischer–Tropsch-to-olefins catalyst indicates a role for CO 2 perturbing the equilibrium between iron carbides and oxides.
View article: Spectroscopic investigations of a pharmaceutical solid form analogue: pyrimethanil <scp>l</scp> -tartaric acid hemi-cocrystal
Spectroscopic investigations of a pharmaceutical solid form analogue: pyrimethanil <span>l</span> -tartaric acid hemi-cocrystal Open
Vibrational analysis of a model cocrystal system: pyrimethanil (an anilinopyrimidine fungicide) and l -tartaric acid (PYL-LTA-CC).
View article: Toward a Generic Model for Phosgene Synthesis Catalysis over Activated Carbon
Toward a Generic Model for Phosgene Synthesis Catalysis over Activated Carbon Open
A reaction model was recently been postulated to describe the phosgene synthesis process over an activated carbon catalyst. That body of work exclusively considered a single grade of activated carbon (Donau Supersorbon K40), raising the is…
View article: The application of an alumina-supported Ni catalyst for the hydrogenation of nitrobenzene to aniline
The application of an alumina-supported Ni catalyst for the hydrogenation of nitrobenzene to aniline Open
Connecting to a methodology developed for defining the relationship between catalyst morphology, adsorbate orientation/location and product distributions with Pd/Al2O3 catalysts, a commercial grade 20 wt% Ni/Al2O3 catalyst (HTC-500), is in…
View article: The application of alumina supported Pd catalysts for high selectivity aniline synthesis catalysis at elevated temperatures: Site-selective chemistry
The application of alumina supported Pd catalysts for high selectivity aniline synthesis catalysis at elevated temperatures: Site-selective chemistry Open
The industrial scale heterogeneously catalysed hydrogenation of nitrobenzene to produce aniline is ideally suited to the incorporation of heat recovery strategies. However, a range of by-products may be observed. Thus, discerning the origi…
View article: Inelastic Neutron Scattering Studies of Propene and 1-Octene Oligomerisation in H-ZSM-5
Inelastic Neutron Scattering Studies of Propene and 1-Octene Oligomerisation in H-ZSM-5 Open
Neutron scattering methods such as quasielastic neutron scattering (QENS) and inelastic neutron scattering (INS) have been used to study the reactivity of propene and 1-octene over the acid zeolite catalyst H-ZSM-5. The high activity of th…
View article: On the transition to gasoline-to-olefins chemistry in the cracking reactions of 1-octene over H-ZSM-5 catalysts
On the transition to gasoline-to-olefins chemistry in the cracking reactions of 1-octene over H-ZSM-5 catalysts Open
The cracking reactions of 1-octene over H-ZSM-5 zeolite are studied via micro-reactor and off-line spectroscopic techniques over a period of up to 72 hours on stream and a temperature range of 473 – 673 K. 1-Octene is found to react via a …
View article: Neutron Scattering Studies of Heterogeneous Catalysis
Neutron Scattering Studies of Heterogeneous Catalysis Open
Understanding the structural dynamics/evolution of catalysts and the related surface chemistry is essential for establishing structure-catalysis relationships, where spectroscopic and scattering tools play a crucial role. Among many such t…
View article: The adsorption of nitrobenzene over an alumina-supported palladium catalyst: an infrared spectroscopic study
The adsorption of nitrobenzene over an alumina-supported palladium catalyst: an infrared spectroscopic study Open
The adsorption geometry of nitrobenzene over a 5 wt% Pd/Al 2 O 3 catalyst is investigated by a combination of infrared spectroscopy and DFT calculations.
View article: Operational parameters relevant to the examination of phosgene synthesis catalysis
Operational parameters relevant to the examination of phosgene synthesis catalysis Open
A description of an experimental apparatus to investigate phosgene synthesis over activated carbon catalysts is given. Reaction without catalyst, construction of reaction mass balances and minimization of mass transfer limitations are cons…
View article: Neutron scattering studies of the methanol-to-hydrocarbons reaction
Neutron scattering studies of the methanol-to-hydrocarbons reaction Open
The application of neutron scattering techniques (inelastic neutron scattering, quasi-elastic neutron scattering and neutron diffraction) to explore concepts connected with the methanol-to-hydrocarbon reaction over the zeolite ZSM-5 are co…
View article: <i>In situ</i> real-time neutron imaging of gaseous H<sub>2</sub> adsorption and D<sub>2</sub> exchange on carbon-supported Pd catalysts
<i>In situ</i> real-time neutron imaging of gaseous H<sub>2</sub> adsorption and D<sub>2</sub> exchange on carbon-supported Pd catalysts Open
Real time neutron imaging allows both physical and chemical changes of a catalyst inside a reaction cell to be seen.
View article: Counting the Acid Sites in a Commercial ZSM-5 Zeolite Catalyst
Counting the Acid Sites in a Commercial ZSM-5 Zeolite Catalyst Open
This work investigates the acid sites in a commercial ZSM-5 zeolite catalyst by a combination of spectroscopic and physical methods. The Brønsted acid sites in such catalysts are associated with the aluminum substituted into the zeolite la…
View article: Combining quasielastic neutron scattering and molecular dynamics to study methane motions in ZSM-5
Combining quasielastic neutron scattering and molecular dynamics to study methane motions in ZSM-5 Open
Quasi-elastic neutron scattering (QENS) and molecular dynamics (MD) simulations are applied in combination to investigate the dynamics of methane in H-ZSM-5 zeolite catalysts used for methanol-to-hydrocarbons reactions. Methane is employed…
View article: Mechanistic Insight Into the Application of Alumina-Supported Pd Catalysts for the Hydrogenation of Nitrobenzene to Aniline
Mechanistic Insight Into the Application of Alumina-Supported Pd Catalysts for the Hydrogenation of Nitrobenzene to Aniline Open
Two Pd/γ-Al2O3 catalysts are examined for the vapor phase hydrogenation of nitrobenzene over the temperature range of 60-200 °C. A 1 wt % catalyst is selected as a reference material that is diluted with γ-alumina to …
View article: Interaction of Methanol over CsCl- and KCl-Doped η-Alumina and the Attenuation of Dimethyl Ether Formation
Interaction of Methanol over CsCl- and KCl-Doped η-Alumina and the Attenuation of Dimethyl Ether Formation Open
As part of a program to investigate aspects of surface chemistry relevant to methyl chloride synthesis catalysis, the interaction of methanol with η-alumina doped with either CsCl or KCl in the range 0.01-1.0 mmol g(cat) -1…
View article: Toward High Selectivity Aniline Synthesis Catalysis at Elevated Temperatures
Toward High Selectivity Aniline Synthesis Catalysis at Elevated Temperatures Open
In connection with an initiative to enhance heat recovery from the large-scale operation of a heterogeneously catalyzed nitrobenzene hydrogenation process to produce aniline, it is necessary to operate the process at elevated temperatures …
View article: A Spectroscopic Paradox: The Interaction of Methanol with ZSM-5 at Room Temperature
A Spectroscopic Paradox: The Interaction of Methanol with ZSM-5 at Room Temperature Open
The adsorption of methanol in HZSM-5 at low temperatures has long been regarded as an associative process involving hydrogen bonding to the acidic zeolite hydroxyl groups. Recent studies employing inelastic neutron scattering spectroscopy …
View article: Net Zero and Catalysis: How Neutrons Can Help
Net Zero and Catalysis: How Neutrons Can Help Open
Net Zero has the aim of achieving equality between the amount of greenhouse gas emissions produced and the amount removed from the atmosphere. There is widespread acceptance that for Net Zero to be achievable, chemistry, and hence catalysi…
View article: The Characterisation of Hydrogen on Nickel and Cobalt Catalysts
The Characterisation of Hydrogen on Nickel and Cobalt Catalysts Open
View article: A Comparison of Experimental Procedures for the Application of Infrared Spectroscopy to Probe the Surface Morphology of an Alumina-Supported Palladium Catalyst
A Comparison of Experimental Procedures for the Application of Infrared Spectroscopy to Probe the Surface Morphology of an Alumina-Supported Palladium Catalyst Open
Structure/function relationships in heterogeneous catalysis play an important role in catalyst design strategies. The combination of chemisorption of suitable probe molecules alongside application of infrared spectroscopy is an established…
View article: An Inelastic Neutron Scattering Investigation of the Temporal Behaviour of the Hydrocarbonaceous Overlayer of a Prototype Fischer-Tropsch to Olefins Catalyst
An Inelastic Neutron Scattering Investigation of the Temporal Behaviour of the Hydrocarbonaceous Overlayer of a Prototype Fischer-Tropsch to Olefins Catalyst Open
A dual sodium and sulfur promoted haematite, representative of a candidate Fischer-Tropsch to olefins (FTO) catalyst, is prepared and contrasted with the performance of an unpromoted hematite sample in the ambient pressure CO hydrogenation…
View article: New Spectroscopic Insight into the Deactivation of a ZSM‐5 Methanol‐to‐Hydrocarbons Catalyst
New Spectroscopic Insight into the Deactivation of a ZSM‐5 Methanol‐to‐Hydrocarbons Catalyst Open
The nature of the hydrocarbon pool at different stages of the methanol‐to‐hydrocarbons reaction over ZSM‐5 is examined. A combination of reaction testing, analytical and spectroscopic techniques is employed to investigate changes in the na…
View article: Phosgene Synthesis Catalysis: The Influence of Small Quantities of Bromine in the Chlorine Feedstream
Phosgene Synthesis Catalysis: The Influence of Small Quantities of Bromine in the Chlorine Feedstream Open
The effect of relatively low concentrations of Br2(g) in the Cl2(g) feedstock for phosgene synthesis catalysis via the reaction of CO(g) and Cl2(g) over activated carbon (Donau Supersorbon K40) i…
View article: Studies of propene conversion over H-ZSM-5 demonstrate the importance of propene as an intermediate in methanol-to-hydrocarbons chemistry
Studies of propene conversion over H-ZSM-5 demonstrate the importance of propene as an intermediate in methanol-to-hydrocarbons chemistry Open
A role for propene as an intermediate in methanol-to-hydrocarbons chemistry over H-ZSM-5 is considered.
View article: Advanced approaches: general discussion
Advanced approaches: general discussion Open
Simon Kondrat opened discussion of the paper by Valerii Bukhtiyarov: The influence on butene selectivity by using metal acetate precursors is very interesting. Your work and findings remind me of previous work by myself and others on the i…
View article: Hydrogenation on Palladium Nanoparticles Supported by Graphene Nanoplatelets
Hydrogenation on Palladium Nanoparticles Supported by Graphene Nanoplatelets Open
Pd nanoparticles (1 wt %; mean size ∼4 nm) were supported on ∼2 μm sized, but few nanometers thick, graphene nanoplatelets (GNPs) and compared to 1 wt % Pd on activated carbon or γ-alumina. Catalyst morphology, specific surface area, and P…
View article: The application of inelastic neutron scattering to investigate iron-based Fischer-Tropsch to olefins catalysis
The application of inelastic neutron scattering to investigate iron-based Fischer-Tropsch to olefins catalysis Open