Noble metals exhibit broad arrange of applications in industry and several aspects of human life which are becoming more and more prevalent in modern times. Due to their limited sources and ...constantly and consistently expanding demand, recycling of secondary and waste materials must accompany the traditional mineral extractions. This Minireview covers the most recent solvometallurgical developments in regeneration of Pd, Pt, Rh, Ru, Ir, Os, Ag and Au with emphasis on sustainability and selectivity. Processing—by selective oxidative dissolution, reductive precipitation, solvent extraction, co‐precipitation, membrane transfer and trapping to solid media—of eligible multi‐metal substrates for recycling from waste printed circuit boards to end‐of‐life automotive catalysts are discussed. Outlook for possible future direction for noble metal recycling is proposed with emphasis on sustainable approaches.
Recently developed solvometallurgical methods with the emphasis on green reagents, solvents and strategies are discussed in recycling noble metals Pd, Pt, Rh, Ru, Ir, Os, Ag and Au. Sustainable and separative techniques including selective dissolution, precipitation and coordination for processing of multi‐metal substrates like end of life catalysts and WEEE are highlighted.
This is the first report on the synthesis and characterization of N-iodo sulfoximines. The synthesis was designed as a room temperature one-pot cascade reaction from readily available sulfides as ...starting compounds, converted into sulfoximines by reaction with ammonium carbonate and (diacetoxyiodo)benzene, followed by iodination with N-iodosuccinimide or iodine in situ, in up to 90% isolated yields, also at a multigram scale. Iodination of aryls with N-iodo sulfoximines, oxidation, and conversion to N-SCF3 congeners have been demonstrated.
NaSH·H
2
O and 37% aqueous solution of HCl were employed in reduction of sulfoxides to sulfides at room or elevated temperature in the absence of organic reducing agent and solvent-free reaction ...conditions. Operationally simple transformation took place in the presence of air and in the absence of heavy metals and organic reagents, yielding sodium chloride and sulfur as non-hazardous waste. Heterogeneous reaction conditions proved challenging, particularly in the cases of more hydrophobic substrates, requiring elevated amount of reactants and temperature. Products were isolated by extraction with tert-butyl methyl ether and "filtered" over a short pad of silica gel. Scale-up reaction was demonstrated, including completely solvent-free isolation and purification of the product. A potential reaction course was proposed.
Gold is a scarce element in the Earth's crust but indispensable in modern electronic devices. New, sustainable methods of gold recycling are essential to meet the growing eco‐social demand of gold. ...Here, we describe a simple, inexpensive, and environmentally benign dissolution of gold under mild conditions. Gold dissolves quantitatively in ethanol using 2‐mercaptobenzimidazole as a ligand in the presence of a catalytic amount of iodine. Mechanistically, the dissolution of gold begins when I2 oxidizes Au0 and forms a AuII2− species, which undergoes subsequent ligand‐exchange reactions and forms a stable bis‐ligand AuI complex. H2O2 oxidizes free iodide and regenerated I2 returns back to the catalytic cycle. Addition of a reductant to the reaction mixture precipitates gold quantitatively and partially regenerates the ligand. We anticipate our work will open a new pathway to more sustainable metal recycling with the utilization of just catalytic amounts of reagents and green solvents.
Gold can be dissolved in a sustainable manner with common household chemicals: iodine solution in ethanol, resembling diluted iodine tincture, green oxidant hydrogen peroxide and 2‐mercaptobenzimidazole, a compound used in medicinal applications. Catalytic reactions and green solvents are the basis for sustainable development and recycling of precious metals like gold.
Gold is a valuable metal that can be dissolved with common household chemicals as reported by Timo Repo et al. in their Research Article (e202117587). By applying catalytic iodine, aqueous hydrogen ...peroxide and 2‐mercaptobenzimidazole, gold promptly dissolves in ethanol. Catalytic reactions and environmentally benign solvents and reagents are the basis for sustainable development and a gateway to a greener future of precious metals recycling.
Abstract
The unique structure of 2.2paracyclophane (PCP) with its rigidity, stability, and planar chirality has gained significant attention in polymer and material research. In this work, the ...incorporation of amino‐functionalized PCPs within polymers of intrinsic microporosity (PIMs) is reported for the first time. Three different PCP‐PIMs were prepared via a Tröger's base formation mechanism, and their structures characterized via solid‐state NMR, MALDI‐TOF, and SEM. Their porosity was evaluated using gas adsorption (N
2
and CO
2
) based on theoretical calculations such as Brunauer–Emmett–Teller (BET), NLDFT pore size distribution (PSD) and ideal IAST CO
2
/N
2
selectivity (15/85), a crucial separation when considering the capture of CO
2
from flue gas. The surface areas were found to be between 200–230 m
2
g
−1
while the selectivity for CO
2
/N
2
ranged from 46 to 70.
Noble metals exhibit broad arrange of applications in industry and several aspects of human life which are becoming more and more prevalent in modern times. Due to their limited sources and ...constantly and consistently expanding demand, recycling of secondary and waste materials must accompany the traditional mineral extractions. This Minireview covers the most recent solvometallurgical developments in regeneration of Pd, Pt, Rh, Ru, Ir, Os, Ag and Au with emphasis on sustainability and selectivity. Processing—by selective oxidative dissolution, reductive precipitation, solvent extraction, co‐precipitation, membrane transfer and trapping to solid media—of eligible multi‐metal substrates for recycling from waste printed circuit boards to end‐of‐life automotive catalysts are discussed. Outlook for possible future direction for noble metal recycling is proposed with emphasis on sustainable approaches.
Recently developed solvometallurgical methods with the emphasis on green reagents, solvents and strategies are discussed in recycling noble metals Pd, Pt, Rh, Ru, Ir, Os, Ag and Au. Sustainable and separative techniques including selective dissolution, precipitation and coordination for processing of multi‐metal substrates like end of life catalysts and WEEE are highlighted.
Monitoring infectious diseases is one of the most important pillars of preventative veterinary medicine in zoological collections. The zoo environment offers a great variety of different animal ...species living in proximity and in contact with small wild animals and vectors (e.g., ticks and mosquitos). In this context, tick-borne encephalitis virus (TBEV), Usutu virus (USUV), and West Nile virus (WNV) causing vector-borne diseases are emerging pathogens that raise concern. The aim of the study was to detect antibodies to selected flaviviruses in various animal species in the Ljubljana Zoo, Slovenia. In total, 874 sera from 96 animal species were tested for antibodies to TBEV by enzyme-linked immunosorbent assays (ELISA); positive samples were confirmed by a virus neutralization test (VNT) using TBEV, WNV, and USUV antigens. Antibodies to TBEV were detected by ELISA in 3.9% (34/874) of zoo animals, with 4% (30/753) in mammals and 5% (4/86) in birds; the sera of reptiles (
n
= 34) and amphibians (
n
= 1) were negative. Antibodies to TBEV were confirmed by VNT in 11 mammals; one bird was positive for both WNV and USUV. The mixture of exotic animal species and their contact with wild animals and vectors such as ticks and mosquitos suggest that screening of infectious diseases in zoo animals might provide good insight into the epizootological situation of the area. This is the first survey of TBEV, WNV, and USUV in a zoological collection in Slovenia.
The delivery of vaccines plays a pivotal role in influencing the strength and longevity of the immune response and controlling reactogenicity. Mucosal immunization, as compared to parenteral ...vaccination, could offer greater protection against respiratory infections while being less invasive. While oral vaccination has been presumed less effective and believed to target mainly the gastrointestinal tract, trans-buccal delivery using mucoadhesive films (MAF) may allow targeted delivery to the mucosa. Here we present an effective strategy for mucosal delivery of several vaccine platforms incorporated in MAF, including DNA plasmids, viral vectors, and lipid nanoparticles incorporating mRNA (mRNA/LNP). The mRNA/LNP vaccine formulation targeting SARS-CoV-2 as a proof of concept remained stable within MAF consisting of slowly releasing water-soluble polymers and an impermeable backing layer, facilitating enhanced penetration into the oral mucosa. This formulation elicited antibody and cellular responses comparable to the intramuscular injection, but also induced the production of mucosal IgAs, highlighting its efficacy, particularly for use as a booster vaccine and the potential advantage for protection against respiratory infections. The MAF vaccine preparation demonstrates significant advantages, such as efficient delivery, stability, and simple noninvasive administration with the potential to alleviate vaccine hesitancy.
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