The conversion of CO2 into desirable multicarbon products via the electrochemical reduction reaction holds promise to achieve a circular carbon economy. Here, we report a strategy in which we modify the surface of bimetallic silver-copper catalyst with aromatic heterocycles such as thiadiazole and triazole derivatives to increase the conversion of CO2 into hydrocarbon molecules. By combining operando Raman and X-ray absorption spectroscopy with electrocatalytic measurements and analysis of the reaction products, we identified that the electron withdrawing nature of functional groups orients the reaction pathway towards the production of C2+ species (ethanol and ethylene) and enhances the reaction rate on the surface of the catalyst by adjusting the electronic state of surface copper atoms. As a result, we achieve a high Faradaic efficiency for the C2+ formation of ≈80% and full-cell energy efficiency of 20.3% with a specific current density of 261.4 mA cm−2 for C2+ products.

Limiting resources of fossil fuels and environmental issues inevitably require more efficient utilization of solar energy. Photocatalytic production of hydrogen is identified as one of the most promising routes for developing clean and sustainable energy. However, engineering of low-cost materials exhibiting high catalytic activity in the entire range of solar spectrum is still a challenge. Here we report, for the first time, simple, easily scalable and environmentally friendly synthesis of stable Ti@TiO 2 core-shell nanoparticles exhibiting photocatalytic activity in hydrogen production under Vis/NIR light irradiation without any noble metals. Stable to oxidation core-shell Ti@TiO 2 nanoparticles have been obtained by the simultaneous actions of ultrasound and hydrothermal treatment on air-passivated titanium metal nanoparticles in pure water. The obtained material is composed of quasi-spherical Ti particles (20-80 nm) coated by 5-15 nm crystals of defect-free anatase with small amounts of rutile. In contrast to pristine TiO 2 , the Ti@TiO 2 nanoparticles extend the photo response from UV to NIR light region due to the light absorption by nonplasmonic Ti core. In MeOH-H 2 O solutions, the Ti@TiO 2 nanoparticles exhibit the strongest catalytic activity in H 2 formation under joint effect of Vis/NIR light and heat. Isotopic study using MeOH-D 2 O solutions suggested the reaction mechanism involving electron holes accumulation in semiconducting TiO 2 shell via charge separation and multiple charge-transfer steps that follow Ti interband transition. The electron transport from Ti core presumably occurs through the junctions between TiO 2 crystals at the surface of core-shell nanoparticles.

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) 1-x (CeO 2 ) 2x (ZrO 2 ) 2 mixed oxides (LCZ) where 0 ≤ x ≤ 1 were synthesised from commercial La 2 O 3 , CeO 2 and ZrO 2 powders and co-melted in a 2-kW solar furnace. These samples were re-oxidised in air at temperatures that ranged from 900 K to 1100 K. The microstructures of the LC, LCZ and CZ oxides were investigated by XPS and XRD. Core-level spectroscopy (XPS) has been used to study electronic states (III) and (IV) of the Ce 3 d 5/2 and Ce 3 d 3/2 levels. The resolved components of the Ce 3 d 3/2 , 5/2 features were identified. The rate of Ce 3+ and Ce 4+ states were calculated for different values of x (0.1-1). The nature of the chemical bonds of Ce and O were determined from the Ce 3 d 3/2,5/2 and O 1 s photoelectron peaks, respectively.The XRD study revealed the presence of solid solutions (LCZ and CZ). The presence of crystalline phases (pyrochlore and fluoritelike structures) depends on the value of x. A decrease in the lattice parameter was observed with increasing x. La atoms were substituted by Ce atoms in a solid solution, and the oxygen vacancies were filled. The amount of fluorite-like phase increases with an increasing amount of Ce atoms.

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Using a simple slow decomposition method of nitrate precursors, high-surface area platinumdoped ceria with a crystallite size of 9 nm can be prepared. The catalytic performance of the compound can be tuned by changing the reduction temperature under hydrogen (300°C, 500°C and 700°C). The catalyst treated at 300°C shows the best catalytic performance, being active at room temperature. The materials were analysed using a combination of structural characterization methods (X-ray diffraction (XRD), nitrogen physisorption, high angle annular dark field scanning transmission electron microscopy (HAADF-STEM)), surface sensitive methods (X-ray photoelectron spectroscopy (XPS), H 2-chemisorption and H 2temperature-programmed reduction (TPR)) and X-ray absorption fluorescence spectroscopy (XAFS). HAADF-STEM and XAFS analysis suggests successful doping of platinum in the ceria lattice. After pretreatment at 300°C, the situation is slightly different. While no defined platinum nanoparticles can be identified on the surface, some platinum is in a reduced state (XPS, H 2-chemisorption).

In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane.