Mixed Cu‐Co hydroxycarbonates of the type (Cu1–xCox)2CO3(OH)2 have been synthesized over the whole range of Cu‐Co substitution (0≤x≤1) by co‐precipitation and their electrocatalytic activity in the oxidation reactions of ethanol (EOR), ethylene glycol (EGOR) and glycerol (GOR) in alkaline environment was evaluated to retrieve composition–activity correlations. Generally, cobalt incorporation led to higher activities for the alcohol oxidation (AOR) compared to the Cu‐only material and the results are compared with the competing oxygen evolution reaction (OER). On the Cu‐Co hydroxycarbonates, the electrooxidation of vicinal alcohols such as glycerol and ethylene glycol requires lower overpotentials than EOR and OER. Cu leaching from the hydroxycarbonate structure was observed in the presence of vicinal alcohols. The impact of chemical and electrochemical leaching of copper from the catalysts has been studied. The chemically leached catalyst was found to show increased AOR activity compared to other hydroxycarbonates, enabling the formation of larger amounts of formic acid during GOR measured in a circular flow cell electrolyzer. The results highlight that Cu‐Co hydroxycarbonates can be used as precursors to generate electrocatalytically active materials from Cu‐Co hydroxycarbonates for the AOR in alkaline solution.

We report on an inverse model Cu/MgO methanol catalyst modified with 5 % zinc oxide at the Cu surface to element‐specifically probe the interplay of metallic copper and zinc oxide during reductive activation. The structure of copper and zinc was unraveled by in situ X‐ray diffraction (XRD) and in situ X‐ray absorption spectroscopy (XAS) supported by theoretical modelling of the extended X‐ray absorption fine structure and X‐ray absorption near‐edge structure spectra. Temperature‐programmed reduction in H2 during in situ XAS showed that copper was reduced starting at 145 °C. With increasing reduction temperature, zinc underwent first a geometrical change in its structure, followed by reduction. The reduced zinc species were identified as surface alloy sites, which coexisted from 200 °C to 340 °C with ZnO species at the copper surface. At 400 °C Zn−Cu bulk‐alloyed particles were formed. According to in situ XRD and in situ XAS, about half of the ZnO was not fully reduced, which can be explained by a lack of contact with copper. Our experimental results were further substantiated by density functional theory calculations, which verified that ZnO with neighboring Cu atoms reduced more easily. By combining these results, the distribution, phase and oxidation state of Zn species on Cu were estimated for the activated state of this model catalyst. This insight into the interplay of Cu and Zn forms the basis for deeper understanding the active sites during methanol synthesis.

The synthesis of Mg-substituted copper hydroxycarbonates by constant-pH co-precipitation with subsequent ageing of the precipitate has been studied in detail. This allowed the retrieval of crystalline magnesian malachite samples, which showed a "radical-sign-shaped" pH drop and the blue/green color change during ageing that is well-known from the analogous Cu/Zn system. The crystallization of Cu-rich samples has been studied elaborately by means of powder diffraction, pair distribution function (PDF), and infrared spectroscopy, thus elucidating the ageing chemistry of Cu,Mg hydroxycarbonates in general. It was found that up to 17 % Mg can be incorporated into the crystalline malachite using a synthesis route comparable to that established for Cu/ZnO catalysts, but with drastically elongated precipitate ageing times. For higher Mg contents, a step-like pH drop was observed instead, and an amorphous variant of the hydroxycarbonate, referred to as "magnesian georgeite", could be isolated. From such a Mg-rich sample (Cu/Mg 70 : 30 at. %), a Cu/MgO catalyst has been prepared that shows high activity and good stability in CO hydrogenation to methanol over 800 hrs. time on stream.

Zinc selenide nanospheres were prepared from a diphenyl diselenide precursor and halozincate(ii) ionic liquids via a microwave-assisted ionothermal route.

The phase diagram Li−Mg−N−H offers ample opportunities for potential hydrogen storage systems. Three systems based on lithium nitride, Li 3 N, were investigated by time-resolved in situ methods (thermal analysis, Xray and neutron diffraction) at temperatures up to 703 K and hydrogen gas pressures up to 9.4 MPa. Pure lithium nitride reacts in a one-step reaction to lithium amide according to Li 3 N + 2H 2 → LiNH 2 + 2LiH at 1.0 MPa hydrogen pressure. Equimolar mixtures of lithium nitride with magnesium hydride, both at 1.5 and 9.4 MPa hydrogen gas pressure, react in the same way up to 543 K, i.e., magnesium hydride does not participate in the reaction. At higher temperatures, lithium magnesium nitride is formed according to the endothermic reaction LiNH 2 + MgH 2 → LiMgN + 2H 2 at moderate (≤1.5 MPa) and via the exothermic reaction Li 3 N + MgH 2 → LiMgN + 2LiH at higher hydrogen gas pressures (5.0 MPa). Mixed imide Li 2 Mg(NH) 2 is formed when an excess of Li 3 N is used in the reaction. The hydrogenation of mixtures of lithium nitride with magnesium starts with the formation Li 2 NH and Li 4 NH, followed by the mixed imide Li 2 Mg(NH) 2 at higher temperatures and finally the formation of Mg 3 N 2 and LiH. Deuterides react accordingly.