Synthesis, characterization and catalytic performances of ruthenium-based catalysts for the acceptorless dehydrogenative coupling of butanol

A growing interest towards new sources of energy has led in recent years to the development of a new generation of catalysts for alcohol dehydrogenative coupling (ADC). This green, atom-efficient reaction is capable of turning alcohol derivatives into higher value and chemically more attractive ester molecules, and it finds interesting applications in the transformation of the large variety of products deriving from biomass. In the present work, a new series of ruthenium-PNP pincer complexes are investigated for the transformation of 1-butanol, one of the most challenging substrates for this type of reactions, into butyl butyrate, a short-chain symmetrical ester widely used in flavor industries. Since the reaction kinetics depends on hydrogen diffusion, the study aimed at identifying proper reactor type and right catalyst concentration to avoid mass transfer interferences and to get dependable data. A comparison between catalytic activities and productivities has been made to establish the role of the different ligands bonded both to the PNP binder and to the ruthenium metal center, and hence to find the best catalyst for this type of reaction.

Misurazione della Sostenibilità in Azienda. Approccio Quantitativo all'Analisi della Letteratura attraverso Bibliografic Coupling.

L'elaborato si impegna ad esporre i risultati derivanti da una revisione estensiva della letteratura riguardante le pratiche di misurazione della sostenibilità in azienda. Si è scelto un approccio al problema di impostazione bibliometrico, consistente in analisi statistiche di dati bibliografici ricavabili osservando le relazioni tra documenti. Si sono utilizzati strumenti di clustering per categorizzare la letteratura ed individuare le aree di maggior interesse potenziali per aziende che desiderino investire con successo nella sostenibilità. Come risultato, si è ottenuta una chiara identificazione delle principali tematiche che devono essere tenute in considerazione nell’affrontare valutazioni relative alla misurazione e valorizzazione dei concetti di sostenibilità e impatto ambientale in ambito aziendale. Il presente lavoro si presenta inoltre come guida metodologica per un approccio quantitativo alla revisione della letteratura, adattabile ed applicabile in maniera iterativa per un continuo monitoraggio del tema o per indagini in altri ambiti. Questa tesi si pone dunque come base per ricerche e analisi successive finalizzate alla comprensione della letteratura.

Evaluation of most promising options for the C1 to C2-coupling: alternative formate coupling

This thesis work contains an overview of potential alternative options to couple formate produced from CO2 with other coupling partners than formate itself. Ultimately, the intent is to produce high value chemicals from CO2 at a high selectivity and conversion, whilst keeping the required utility of electrons in the electrochemical CO2 conversion at a minimum. To select and find new coupling partners, a framework was developed upon which a broad variety of candidates were assessed and ranked. A multi-stage process was used to select first potential classes of molecules. For each class, a variety of commercially available compounds was analysed in depth for its potential suitability in the reaction with the active carbonite intermediate. This analysis has shown that a wide variety of factors come into play and especially the reactivity of the hydride catalyst poses a mayor challenge. The three major potential classes of compounds suitable for the coupling are carbon oxides (CO2 & CO), and aldehydes. As a second step the remaining options were ranked to identify which compound to test first. In this ranking the reactants sustainability, ease of commercial operation and commercial attractiveness of the compound were considered. The highest-ranking compounds that proposed the highest potential are CO2, benzaldehyde and para-formaldehyde. In proof-of-principle experiments CO2 could successfully be incorporated in the form of carbonate, oxalate and potentially formate. The overall incorporation efficiency based on the hydride consumption was shown to be 50%. It is suggested to continue this work with mechanistic studies to understand the reaction in detail as, based on further gained knowledge, the reaction can then be optimized towards optimal CO2 incorporation in the form of oxalate.

Exploring the Higgs-muon coupling at a multi-TeV muon collider

We investigate the potential of a high-energy muon collider in measuring the muon Yukawa coupling (y_μ) in the production of two, three and four heavy bosons via muon-antimuon annihilations. We study the sensitivity of these processes to deviations of y_μ from the Standard Model prediction, parametrized by an effective dimension-6 operator in the Standard Model Effective Field Theory (SMEFT) framework. We also consider the κ framework, in which the deviation is simply parametrized by a strength modification of the μ+μ−h vertex alone. Both frameworks lead to an energy enhancement of the cross sections with one or more vector bosons, although the κ framework yields stronger effects, especially for the production of four bosons. On the contrary, for purely-Higgs final states the cross section is suppressed in the κ framework, while it is extremely sensitive to deviations in the SMEFT. We show that the triple-Higgs production is the most sensitive process to spot new physics effects on y_μ.