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.

Temporal Framing in the Conte: From Theoretical Debate to Oral Story Performance

This article explores ‘temporal framing’ in the oral conte. The starting point is a recent theoretical debate around the temporal structure of narrative discourse which has highlighted a fundamental tension between the approaches of two of the most influential current theoretical models, one of which is ‘framing theory’. The specific issue concerns the role of temporal adverbials appearing at the head of the clause (e.g. dates, relative temporal adverbials such as le lendemain) versus that of temporal ‘connectives’ such as puis, ensuite, etc. Through an analysis of a corpus of contes performed at the Conservatoire contemporain de Littérature Orale, I shall explore temporal framing in the light of this theoretical debate, and shall argue that, as with other types of narrative discourse, framing is primarily a structural rather than a temporal device in oral narrative. In a final section, I shall further argue, using Kintsch’s construction-integration model of narrative processing, that framing is fundamental to the cognitive processes involved in oral story performance.