Herein, we provide an account on the multi-faceted approach to scaling up a low-carbon chemical technology that originates from academia. First, we discuss technical considerations that must be met prior to industrialisation of a process. Then, we discuss the non-technical considerations such as financing, regulatory and IP rights that are required to obtain support for the project.
View Article and Find Full Text PDFIn this work, we looked at the most recent advances in the field of plastics hydrocracking from a technology standpoint. A patent search was supplemented by a literature review to evaluate the development of the hydrocracking technology for plastics recycling. We observed that the patent and academic literature output rapidly increased over the past decade, highlighting the recent emergence of this technology to tackle the plastic waste problem.
View Article and Find Full Text PDFCarbon-carbon bond cleavage mechanisms play a key role in the selective deconstruction of alkanes and polyolefins. Here, we show that the product distribution, which encompasses carbon range and formation of unsaturated and isomerization products, serves as a distinctive feature that allows the reaction pathways of different catalysts to be classified. Co, Ni, or Ru nanoparticles immobilized on amorphous silica-alumina, Zeo-Y and ZSM-5, were evaluated as catalysts in the deconstruction of n-hexadecane model substrate with hydrogen to delineate between different mechanisms, i.
View Article and Find Full Text PDFThis Personal Account reviews the sequence of scientific discoveries that led to a catalytic plastic conversion technology that resulted in the creation of a spin-off company called Plastogaz from the Ecole Polytechnique Fédérale de Lausanne (Switzerland). The story begins with research on the catalytic valorization of CO , carried out by two PhD students and a master student, and the connections and steps subsequently made, ultimately leading to a plastic transformation technology. The Personal Account highlights the value of diverse research topics within a research group, the benefits of connections between chemistry and chemical engineering, that can lead to interesting synergies and atypical breakthroughs.
View Article and Find Full Text PDFColloidal stability was investigated in two types of particle systems, namely, with bare (h-HNT) and polyimidazolium-functionalized (h-HNT-IP-2) alkali-treated halloysite nanotubes in solutions of metal salts and ionic liquids (ILs). The valence of the metal ions and the number of carbon atoms in the hydrocarbon chain of the IL cations (1-methylimidazolium (MIM), 1-ethyl-3-methylimidazolium (EMIM), 1-butyl-3-methylimidazolium (BMIM), and 1-hexyl-3-methylimidazolium (HMIM)) were altered in the measurements. For the bare h-HNT with a negative surface charge, multivalent counterions destabilized the dispersions at low values of critical coagulation concentration (CCC) in line with the Schulze-Hardy rule.
View Article and Find Full Text PDFHerein, we describe the status of bio-derived plastics as well as the existing and emerging technologies that are available for their post-consumer end-of-life valorization. We first present how bio-derived plastics can be produced from renewable materials such as biomass and CO₂. In the second section, we present an overview of the technologies available for the end-of-life, including pyrolysis and gasification and how they can be leveraged towards a circular economy.
View Article and Find Full Text PDFAn automatic methodology based on micro sequential injection analysis coupled to a lab-on-valve system (termed μSIA-LOV) was developed and used to determine the ability of metal-based anticancer compounds to inhibit cyclooxygenase 2 (COX-2) activity. COX-2 may be involved in pathogenesis of cancer and it is overexpressed in several types of solid tumors. Since platinum-based compounds are extensively used in the treatment of cancer, and ruthenium compounds are considered as promising candidates for next generation of non-targeted anticancer drugs, it is interesting to establish whether COX-2 inhibition is relevant to their mode of action.
View Article and Find Full Text PDFIon specific effects of ionic liquid (IL) constituents on the surface charge and aggregation properties of two types of particles (positively charged amidine (AL) and polyimidazolium-functionalized sulfate (SL-IP-2) latexes) were investigated in IL solutions containing different anions and the 1-butyl-3-methylimidazolium cation. For the AL systems, the affinity of IL anions to the particle surface followed the sequence chloride < bromide < nitrate < acetate. The critical coagulation concentration values decreased in the same order indicating that ion specific adsorption determines the surface charge density and the extent of the repulsive interparticle forces.
View Article and Find Full Text PDFCancer is currently one of the deadliest diseases worldwide. Based on the high incidence of this disease, the side effects associated with current chemotherapies and the appearance of drug resistance, considerable efforts have been directed towards the development of new anticancer drugs with new modes of action. Metal-based compounds are particularly attractive candidates due to their metabolic mechanisms, which differ substantially from those of organic drugs.
View Article and Find Full Text PDFThe search for efficient catalysts frequently leads to new homogeneous and heterogeneous catalysts of increasing complexity, and sometimes common, natural, or hybrid natural/synthetic materials that could be used in catalysis are overlooked. For example, the leather industry has produced robust Cr-containing materials for centuries by chemical treatment of animal hides with chromium salts. Herein, the use of chromium-tanned leather as a heterogeneous catalyst for glucose dehydration to 5-hydroxymethylfurfural (5-HMF) and levoglucosenone (LGO) is reported.
View Article and Find Full Text PDFCombining CO2-chemistry with biomass conversion allows renewable polymeric materials including polycarbonates and polyhydroxyurethanes (PHUs) to be generated. The demand for robust materials with modular properties that can be prepared on an industrial scale is important and, to date, the most important polymeric materials are derived from petrochemicals. These materials inevitably result in CO2 emissions, and therefore making robust materials from renewable sources will contribute to a more sustainable society.
View Article and Find Full Text PDFWe report a ruthenium-modified zeolite which efficiently transforms propylene carbonate to propylene glycol and methane, under solvent-free conditions. The catalyst achieved high product selectivity and no significant ageing effect was observed after multiple cycles. The resulting liquid product (water-containing glycol) can be directly used as anti-freeze solution and the gas phase can directly be used as an energy carrier in the form of H -enriched methane.
View Article and Find Full Text PDFMembrane technologies enable the facile separation of complex mixtures of gases, vapours, liquids and/or solids under mild conditions. Simultaneous chemical transformations can also be achieved in membranes by using catalytically active membrane materials or embedded catalysts, in so-called membrane reactors. A particular class of membranes containing or composed of ionic liquids (ILs) or polymeric ionic liquids (pILs) have recently emerged.
View Article and Find Full Text PDFInvited for this month's cover are the groups of Prof. Paul J. Dyson at Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland and Prof.
View Article and Find Full Text PDFPlatinum nanoparticles stabilized by an imidazolium-based cross-linked polymer (with chloride as the counteranion) efficiently catalyzed the oxidation of 5-hydroxymethylfurfural to form 2,5-furandicarboxylic acid in water under mild conditions with oxygen as the oxidant. This catalyst system is explored herein by varying the counteranion, that is, replacing chloride by BF , PF , bis(trifluoromethylsulfonyl)imide, hexanoate, or laurate anions, in the cationic polymer. The counteranion influences the structure of the obtained platinum nanoparticles, the surface electronic properties, and their catalytic activity.
View Article and Find Full Text PDFThere is a growing interest in sustainable heterogeneous catalysts based on organic polymers. Here, we describe a series of polyimidazolium salt catalysts, prepared from the direct reaction of arene-bridged bis- and tris-alkyl halides with trimethylsilylimidazole. The polyimidazolium salts were characterized by spectroscopic and analytical techniques and it was found that their morphology and porosity could be controlled by adjusting the steric parameters of the spacer in the alkyl-halide starting materials.
View Article and Find Full Text PDFN-formylation and N-methylation of amines are important reactions that are used to produce a wide range of key intermediates and compounds. This protocol describes the environmentally benign N-formylation and N-methylation of primary and secondary amines using carbon dioxide (CO) as the carbon source, hydrosilanes as reductants and N-heterocyclic carbenes (NHCs) as catalysts. Using CO as a reagent has the advantage of low cost and negligible toxicity.
View Article and Find Full Text PDFA series of dicationic styrene-functionalized imidazolium-based salts, in which the two imidazolium rings are bridged by a functionalized spacer, are prepared. The salts are polymerized to afford cross-linked imidazolium-based ionic polystyrene materials, which, owing to the presence of the functionalized spaces, should be highly active organocatalysts for the cycloaddition of CO to epoxides to afford cyclic carbonates (CCE reaction). The catalytic activities of the polymers are evaluated in the CCE reaction.
View Article and Find Full Text PDFChem Commun (Camb)
September 2016
The synthesis of cyclic carbonates from epoxides and CO2 is a well-established reaction, whereas the synthesis of cyclic carbonates from diols and CO2 is considerably more challenging, and few efficient catalysts are available. Here, we describe heterocyclic carbene catalysts, including one derived from a cheap and efficient thiazolium salt, for this latter reaction. The reaction proceeds at atmospheric pressure in the presence of an alkyl halide and Cs2CO3.
View Article and Find Full Text PDFThe utilization of CO(2) as a C1 synthon is becoming increasingly important as a feedstock derived from carbon capture and storage technologies. Herein, we describe some of our recent research on carbon dioxide valorization, notably, using organocatalysts to convert CO(2) into carboxylic acid, ester, formyl and methyl groups on various organic molecules. We describe these studies within the broader context of CO(2) capture and valorization and suggest approaches for future research.
View Article and Find Full Text PDFThe catalytic N-formylation and N-methylation of amines using CO2 as the carbon source represents a facile and sustainable approach for the synthesis of pharmaceuticals and natural products. Herein, we describe highly effective and inexpensive thiazolium carbene-based catalysts derived from vitamin B1 for the N-formylation and N-methylation of amines, using polymethylhydrosiloxane (PMHS) as a reducing agent, which operate under ambient conditions.
View Article and Find Full Text PDFIonic liquids doped with I2, usually resulting in the formation of polyiodide anions, are extensively used as electrolytes and in iodination reactions. Herein, NMR spectroscopy and single-crystal X-ray diffraction were used to rationalize the structures of imidazolium-based polyiodide ionic liquids in the liquid and solid states. Combined, these studies show that extensive interactions between the imidazolium cation and the resulting polyiodide anion are present, which have the net effect of lengthening, polarizing, and weakening the I-I bonds in the anion.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2014
N-methylation of amines is an important step in the synthesis of many pharmaceuticals and has been widely applied in the preparation of other key intermediates and chemicals. Therefore, the development of efficient methylation methods has attracted considerable attention. In this respect, carbon dioxide is an attractive C1 building block because it is an abundant, renewable, and nontoxic carbon source.
View Article and Find Full Text PDF