SpaciMS: spatial and temporal operando resolution of reactions within catalytic monoliths

Monolithic catalysts are widely used as structured catalysts, especially in the abatement of pollutants. Probing what happens inside these monoliths during operation is, therefore, vital for modelling and prediction of the catalyst behavior. SpaciMS is a spatially resolved capillary-inlet mass spectroscopy system allowing for the generation of spatially resolved maps of the reactions within monoliths. In this study SpaciMS results combined with 3D CFD modelling demonstrate that SpaciMS is a highly sensitive and minimally invasive technique that can provide reaction maps as well as catalytic temporal behavior. Herein we illustrate this by examining kinetic oscillations during a CO oxidation reaction over a Pt/Rh on alumina catalyst supported on a cordierite monolith. These oscillations were only observed within the monolith by SpaciMS between 30 and 90% CO conversion. Equivalent experiments performed in a plug-flow reactor using this catalyst in a crushed form over a similar range of reaction conditions did not display any oscillations demonstrating the importance of intra monolith analysis. This work demonstrates that the SpaciMS offers an accurate and comprehensive picture of structured catalysts under operation.

Using temporal analysis of products and flux response technology to determine diffusion coefficients in catalytic monoliths

The importance of accurately measuring gas diffusivity in porous materials has led to a number of methods being developed. In this study the Temporal Analysis of Products (TAP) reactor and Flux Response Technology (FRT) have been used to examine the diffusivity in the washcoat supported on cordierite monoliths. Herein, the molecular diffusion of propane within four monoliths with differently prepared alumina/CeZrOx washcoats was investigated as a function of temperature. Moment-based analysis of the observed TAP responses led to the calculation of the apparent intermediate gas constant, Kp, that characterises adsorption into the mesoporous network and apparent time delay, tapp, that characterises residence time in the mesoporous network. Additionally, FRT has been successfully adapted as an extensive in situ perturbation technique in measuring intraphase diffusion coefficients in the washcoats of the same four monolith samples. The diffusion coefficients obtained by moment-based analysis of TAP responses are larger than the coefficients determined by zero length column (ZLC) analysis of flux response profiles with measured values of the same monolith samples between 20 and 100 °C ranging from 2–5×10^-9 m² s^-1 to 4–8×10^-10 m² s^-1, respectively. The TAP and FRT data, therefore, provide a range of the lower and upper limits of diffusivity, respectively. The reported activation energies and diffusivities clearly correlate with the difference in the washcoat structure of different monolith samples.

Carbon nanotube modified carbon composite monoliths as superior adsorbents for carbon dioxide capture

Carbon composite monoliths were prepared from a commercial phenolic resin mixed with just 1 wt% of carbon nanotubes (CNTs) followed by carbonization and physical activation with CO. The products possess a hierarchical macroporous-microporous structure and superior CO adsorption properties. In particular, they show the top-ranked CO capacity (52 mg CO per g adsorbent at 25 °C and 114 mmHg) under low CO partial pressures, which is of more relevance for flue gas applications. This matches or exceeds those of carbons produced by complex chemical activation and functionalization. Our study demonstrates an effective way to create narrow micropores through structural modification of carbon composites by CNTs. © 2013 The Royal Society of Chemistry.

Luminescent ionogels based on europium-doped ionic liquids confined within silica-derived networks

Luminescent ionogels were prepared by doping an europium( III) tetrakis beta-diketonate complex into an imidazolium ionic liquid, followed by immobilization of the ionic liquid by confinement in a silica network. The ionogels were obtained by a non-hydrolytic method as perfect monoliths featuring both the transparency of silica and the ionic conductivity performances of ionic liquids. The ionogels contain 80 vol % of ionic liquid. The organic-inorganic hybrid materials showed a very intense red photoluminescence under ultraviolet irradiation. The red emission has a very high coloric purity.

Advanced Ceramic Substrate with Ordered and Designed Micro-Structure for Applications in Automotive Catalysts

This study describes an innovative monolith structure designed for applications in automotive catalysis using an advanced manufacturing approach developed at Imperial College London. The production process combines extrusion with phase inversion of a ceramic-polymer-solvent mixture in order to design highly ordered substrate micro-structures that offer improvements in performance, including reduced PGM loading, reduced catalyst ageing and reduced backpressure.

This study compares the performance of the novel substrate for CO oxidation against commercially available 400 cpsi and 900 cpsi catalysts using gas concentrations and a flow rate equivalent to those experienced by a full catalyst brick when attached to a vehicle. Due to the novel micro-structure, no washcoat was required for the initial testing and 13 g/ft3 of Pd was deposited directly throughout the substrate structure in the absence of a washcoat.

Initial results for CO oxidation indicate that the advanced micro-structure leads to enhanced conversion efficiency. Despite an 79% reduction in metal loading and the absence of a washcoat, the novel substrate sample performs well, with a light-off temperature (LOT) only 15 °C higher than the commercial 400 cpsi sample.

To test the effects of catalyst ageing on light-off temperature, each sample was aged statically at a temperature of 1000 °C, based on the Bench Ageing Time (BAT) equation. The novel substrate performed impressively when compared to the commercial samples, with a variation in light-off temperature of only 3% after 80 equivalent hours of ageing, compared to 12% and 25% for the 400 cpsi and 900 cpsi monoliths, respectively.

The Promise of Peace:Revisiting the Northern Irish Model

The Northern Ireland peace process is often eulogized as a successful model of conflict transformation. Although the process exhibited many of the problems that beset other societies seeking to move from conflict to a negotiated peace (including disagreements over the functioning of institutions and the meanings of cultural symbols, unresolved issues relating to the effects of political violence on victims and survivors and society at large; and the residual presence of violent and political ‘spoiler’ groups), the resilience of political dialogue has proven remarkable.
This collection revisits the promise of ‘a truly historic opportunity for a new beginning’ a decade and a half on from the signing of the Belfast/Good Friday Agreement in 1998. The book will bring together academics from across a number of disciplines, including management and organizational behaviour, law, politics, sociology, archaeology and literature.

The different contributions aim to assess what impact it has made in the legal, policy, and institutional areas it specifically targeted: political reform, human rights and equality provision, working through legacies of the past (including police reform, prisoner release and victims' rights) and the building of new relationships within the island of Ireland and between Ireland and Britain. With the emergence of first-time voters who had no direct experience of the violence the book explores what the Agreement offers for future generations.

The book is the culmination of a 12-month research project sponsored by the British Academy and Leverhulme that addressed the following aspects of the peace process:
Peace walls: The euphemistically named peace walls remain one of the most visible reminders of Northern Ireland’s divisions and they are famously the only material manifestations of the conflict that have grown in number and extent since the 1998 Agreement. They were originally placed between antagonistic neighbouring communities – often at their request – at times of heightened tensions. Research under this theme explored the lack of ongoing engagement with their continuing presences, evolving meanings and impact on the communities that reside beside them needs to be overtly addressed.
Cultural division: Cultural differences have often been seen as lying at the heart of the ‘Irish problem’. Despite this, art and artists have increasingly been seen as having the potential to develop new discourses. Research explored the following questions: What role can the arts play in re-imagining the spaces opened up by the promises of the 1998 Agreement? What implication does the confrontation with the legacies of conflict have for artistic practices? What impact do the arts have on constructions of identity, on narratives of history, and on electoral politics?
Institutional transformation: This strand of research explored the significance of the process of organizational change which followed the establishment of the 1998 on political and other public policy institutions such as the police and prison services. It suggested that the experience and lessons learned from such periods of transition have much to contribute to how Northern Ireland begins to address political polarization in other areas of public service infrastructure, chiefly around the sectarian monoliths of education and housing.
Working through the past: ‘Legacy’ issues have gained increasing prominence since 1998: issues to do with public symbolism (particularly relating to the flying of flags and parading), defining victimhood, securing victims’ rights, recovery of the ‘disappeared’, reintegrating ex- prisoners back into society, and the possibilities for truth recovery and reconciliation have all acquired salient and emotive force. Although the 1998 Agreement promised to ‘honour the dead’ through a ‘new beginning’, it is increasingly unclear as to whether an agreed narrative about the past is possible – or even worthwhile pursuing. Research under this theme looked at the complex relationship between memory, commemoration and violence; how commemorative events are performed, organized, policed and represented. It also addressed the fraught issue of how to come to terms with Northern Ireland’s divided and bloodied past.

The editors are in the process of guiding contributors to adapt their papers, which were presented to a series of workshops on the above themes, to the purposes of the book. In particular, the contributors will be guided to focus on the related aims of assessing the extent of change that has occurred and providing an assessment of what remains to be done. To that end, contributors are asked to engage directly with the questions that close the ‘Introduction’, namely: To what extent has the ‘promise’ of the 1998 Agreement been fulfilled? To what extent has the 1998 Agreement given rise to forms of exclusion? To what extent has the 1998 Agreement shaped new forms of debate, dispute and engagement? In the absence of that guidance having been sent out yet, the outlines below are, for the time being, the abstracts of their original papers.