Herein, we report a novel synthesis of the polymer-supported Brønsted-acidic ionic liquidPS-[(SO3H)4C4Im]-[OTf]as an efficient and recyclable heterogeneous catalyst for the Groebke-Blackburn-Bienaymé (GBB) multicomponent reaction. The catalyst was synthesized from Merrifield resin (polystyrene) and fully characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Its catalytic activity was then evaluated in GBB model reactions, with the optimal conditions determined using 50 mg mmol-1 of PS-[(SO3H)4C4Im]-[OTf] in ethanol as solvent under microwave heating at 150 °C for 1 h. A diverse library of imidazo-fused heterocycles (e.g., imidazo-[1,2-a]-pyridines, imidazo-[2,1-b]-thiazoles, and benzo-[d]-imidazo-[2,1-b]-thiazoles) was synthesized using the optimized conditions and the corresponding products were obtained in moderate to excellent yields (34-91%), depending on the starting aminoazole. Furthermore, the heterogeneous catalyst could be easily recovered by filtration after each reaction cycle and reused for up to six consecutive cycles with no significant loss of integrity as well as catalytic activity (average yield 86 ± 3.5%). These results demonstrated the potential of this polymer-supported Brønsted-acidic ionic liquid as a sustainable catalyst for acid-catalyzed multicomponent reactions applied to the synthesis of nitrogen-based heterocycles of interest in Medicinal Chemistry.

HCN, the direct precursor of oxamide [H2N(C = O)(C = O)NH2)], a superior fertiliser to the urea, can be made via Haber–Bosch (HB) N2 fixation followed by ‘Blausäure‐Methan‐Ammoniak’ (BMA) coupling of NH3/CH4. That composite route is not economically/energetically viable for oxamide fertiliser production (vs. urea). A study of an alternative route to HCN is reported herein. At 1 atm, 40°C, carbon (sustainable charcoal, graphite powder, milled carbon fibres and coal power plant fly ash) and N2 are converted into HCN and CO by non‐thermal plasma (NTP) discharge via C2 diradical/N2 activation. The O‐atoms within the CO result ultimately from water. A stepwise ensemble comprising cyanogen formation (from C2 and N2), its subsequent cleavage to HCN, the water‐gas‐shift‐reaction and Boudouard reaction (CO from CO2/C) is proposed. No conversion of carbon is observed in the absence of NTP, but in its presence, NTP‐synergistic aluminium xerogel additives [prepared from hydrolysis of Al(O‐sec‐Bu)3 in the presence of methanol soluble transition metal salts (Fe, Mg, Mo, Na, Cu, Ag)] augment the reaction selectivity/activity. For the optimal FeII‐xerogel concentrations of 5900–6019 ppm (ca. 0.6% HCN v/v) and 39 032–63 200 ppm (ca. 5% CO v/v) at dissipated energies within a factor of 20 of those for commercial HB‐BMA production of HCN are attained.

The study of electrochemical oxidations has wide-ranging implications, from the development of new electrocatalysts for fuel cells for energy conversion, to the synthesis of fine chemicals. 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) has been used for decades as a sustainable, metal-free mediator for chemical oxidations and is now being used for electrochemical oxidations. We describe here a novel approach to TEMPO-mediated electrooxidations, in which the chemical input and waste generated during electrooxidations of alcohols are minimized by using a multifunctional room temperature ionic liquid (RTIL) to facilitate flow electrosynthesis. Our three-pronged approach involves the following: (1) the use of a recyclable alkylimidazolium-based RTIL to replace the electrolytes and volatile organic solvents typically used in TEMPO-mediated alcohol electrooxidations; (2) pairing alcohol oxidation at the positive electrode with electroreduction of the cationic component of the RTIL at the negative electrode to generate the base required for the electrosynthesis; (3) incorporation of the catalytic TEMPO moiety in our RTIL-based system. We demonstrate the possibilities offered by our strategy using a range of alcohols, illustrating the scope of reactions that can be driven using our strategy and demonstrating the opportunities offered by task-specific, multifunctional RTILs for electroorganic synthesis.

At near ambient conditions (1 atm, 25-40 oC) carbon (sustainable charcoal, graphite powder, milled carbon fibres) and nitrogen are converted into HCN and CO by a Non-Thermal Plasma (NTP) discharge using a previously unrecognised C2 diradical N2 activation route. The O-atoms within the CO result ultimately from carbon-absorbed water. A stepwise ensemble comprising: cyanogen formation (from excited state C2 and N2), its subsequent cleavage to HCN, the Water-Gas-Shift-Reaction (WGSR) and Boudouard reaction (CO from CO2/C) provide the observed products. No conversion of carbon is observed in the absence of NTP, but in its presence, NTP-synergistic aluminium xerogel catalysts [prepared from hydrolysis of Al(O-sec-Bu)3 in the presence of methanol soluble transition metal salts (Fe, Mg, Mo, Na, Cu, Ag)] control the reaction selectivity. For the optimal Fe(II)-xerogel concentrations of 5900-6019 ppm (ca. 0.6% HCN v/v) and 39032-63200 ppm (ca. 5% CO v/v) are reached at dissipated powers of 0.14 W mL-1.min.

Developing sustainable, efficient catalysts for the electrocatalytic reduction of CO2 to valuable products remains a crucial challenge. Our research demonstrates that combining tin with nanostructured carbon support leads to a dynamic interface promoting the transformation of microparticles to nanoparticles directly during the reaction, significantly increasing the formate production up to 5.0 mol h-1 g-1, while maintaining nearly 100% selectivity. Correlative electrochemistry-electron microscopy analysis revealed that the catalyst undergoes an in situ self-optimization during CO2 electroreduction. It has been found that changes in the catalyst are caused by the breakdown of Sn particles driven by electrochemical reactions. The process of pulverization typically results in a decrease in the catalytic activity. However, when Sn particles are pulverized and reach approximately 3 nm in size on the surface of the nanotextured carbon support, the efficiency of the catalyst is maximized. This enhancement occurs because the in situ-formed Sn nanoparticles exhibit better compatibility with the nanotextured support. As a result, the number of electrocatalytically active sites significantly increases, leading to a reduction in charge transfer resistance by more than 2-fold and an improvement in reaction kinetics, which is evidenced by changes in the rate-determining step. Collectively, these factors contribute to a 3.6-fold increase in the catalyst's activity while maintaining its selectivity for formate production.

We illustrate the importance of early career perspectives and diverse partnerships to develop solutions and overcome key challenges to achieve the Sustainable Development Goals.

Abstract A key strategy for minimizing our reliance on precious metals is to increase the fraction of surface atoms and improve the metal-support interface. In this work, we employ a solvent/ligand/counterion-free method to deposit copper in the atomic form directly onto a nanotextured surface of graphitized carbon nanofibers (GNFs). Our results demonstrate that under these conditions, copper atoms coalesce into nanoparticles securely anchored to the graphitic step edges, limiting their growth to 2–5 nm. The resultant hybrid Cu/GNF material displays high selectivity in the CO2 reduction reaction (CO2RR) for formate production with a faradaic efficiency of ~94% at -0.38 V vs RHE and a high turnover frequency of 2.78 × 106 h-1. The Cu nanoparticles adhered to the graphitic step edges significantly enhance electron transfer to CO2. Long-term CO2RR tests coupled with atomic-scale elucidation of changes in Cu/GNF reveal nanoparticles coarsening, and a simultaneous increase in the fraction of single Cu atoms. These changes in the catalyst structure make the onset of the CO2 reduction potential more negative, leading to less formate production at -0.38 V vs RHE, correlating with a less efficient competition of CO2 with H2O for adsorption on single Cu atoms on the graphitic surfaces, revealed by density functional theory calculations.

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