The exploitation of molecular catalysts for CO 2 electrolysis requires their immobilization on the cathode of the electrolyzer. As an illustration of this approach, a Ni-cyclam complex with a cyclam derivative functionalized with a pyrene moiety is synthesized, found to be a selective catalyst for CO 2 electroreduction to CO, and immobilized on a carbon nanotubecoated gas diffusion electrode by using a noncovalent binding strategy. The as-prepared electrode is efficient, selective, and robust for electrocatalytic reduction of CO 2 to CO. Very high turnover numbers (ca. 61460) and turnover frequencies (ca. 4.27 s À 1) are enabled by the novel electrode material in organic solvent-water mixtures saturated with CO 2. This material provides an interesting platform for further improvement.

The development of molecular catalysts for CO2 electroreduction within electrolyzers requests their immobilization on the electrodes. While a variety of methods have been explored for the heterogenization of homogeneous complexes, a novel approach using a hierarchical porous carbon material, derived from a metal–organic framework, is reported as a support for the well‐known molecular catalyst [Re(bpy)(CO)3Cl] (bpy=2,2’‐bipyridine). This cathodic hybrid material, named Re@HPC (HPC=hierarchical porous carbon), has been tested for CO2 electroreduction using a mixture of an ionic liquid (1‐ethyl‐3‐methylimidazolium tetrafluoroborate, EMIM) and water as the electrolyte. Interestingly, it catalyzes the conversion of CO2 into a mixture of carbon monoxide and formic acid, with a selectivity that depends on the applied potential. The present study thus reveals that Re@HPC is a remarkable catalyst, enjoying excellent activity (turnover numbers for CO2 reduction of 7835 after 2 h at −1.95 V vs. Fc/Fc+ with a current density of 6 mA cm−2) and good stability. These results emphasize the advantages of integrating molecular catalysts onto such porous carbon materials for developing novel, stable and efficient, catalysts for CO2 reduction.

Molecular catalysis for selective CO2 electroreduction into CO can be achieved with a variety of metal complexes. Their immobilization on cathodes is required for their practical implementation in electrolytic cells and can benefit from the advantages of a solid material such as easy separation of products and catalysts, efficient electron transfer to the catalyst, and high stability. However, this approach remains insufficiently explored up to now. Here, using an appropriate and original modification of the cyclam ligand, we report a novel [Ni­(cyclam)]2+ complex which can be immobilized on carbon nanotubes. This material, once deposited on a gas diffusion layer, provides a novel electrode which is remarkably selective for CO2 electroreduction to CO, not only in organic solvents but also, more remarkably, in water, with faradic efficiencies for CO larger than 90% and current densities of 5–10 mA cm–2 during controlled potential electrolysis in H-cells.

Environmental contextThe fresh pleasant smell of laundry dried outside in sunlight is recognised by most people, but despite decades of speculation the origin of the smell has not been demonstrated. We show that the smell of line-dried laundry is due to the unique combination of traces of atmospheric hydrocarbons, sunlight and a wet fabric surface. This surface photochemistry is likely to be widespread in the environment on surfaces of natural materials. AbstractIn this study, we find that the drying method is the key element in generating the well-known fresh scent of line-dried laundry, which we argue demonstrates that it is the result of physical and chemical processes occurring on the surface of the fabric. Cotton towels were rinsed with Milli-Q water and dried outdoors, indoors, and outdoors but not exposed to sunlight. The dried towels were placed in sealed Tedlar bags, and the emitted compounds were analysed by using thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) to yield qualitative gas chromatograms and mass spectra. We observed a variety of C5 to C9 oxidised carbon compounds (e.g. aldehydes such as pentanal, hexanal, heptanal, octanal, and nonanal) when the towels were dried outside. These compounds are not observed in the other conditions. Many of these compounds have smells that are subjectively found to be pleasant. The experiments indicate that both UV light and the presence of liquid water are necessary to generate the products. The polar nature of the oxidised compounds may explain why the smell of fresh laundry is relatively long-lasting because hydrogen bonds can form between these compounds and cotton fibres. We therefore propose that oxidative photochemistry on the surface of the drying laundry is responsible for the production of the fresh smell.

The exploitation of molecular catalysts for CO electrolysis requires their immobilization on the cathode of the electrolyzer. As an illustration of this approach, a Ni-cyclam complex, with a cyclam derivative functionalized with a pyrene moiety, was synthesized, shown to be a selective catalyst for CO 2 electroreduction to CO and immobilized on a carbon nanotube-coated gas diffusion electrode by using a non-covalent binding strategy. The as-prepared electrode is efficient, selective, robust for electrocatalytic reduction of CO 2 to CO. Very high turnover numbers (ca. 61460) and turnover frequencies (ca. 4.27 s -1 ) were enabled by the novel electrode material in organic solventwater mixtures saturated in CO 2 . This material provides an interesting platform for further improvement.