• Energy Research

Glycerol Electrooxidation Reaction (GEOR) has been herein investigated on Rh/C and Rh/SnO2-C prepared by polyol method. The particle mean sizes were found to be 2.0 and 1.8 nm in Rh/C and Rh/SnO2-C, respectively. The alloying degree reached 63% in Rh/SnO2-C, confirming a Sn-Rh alloy formation. The activity towards GEOR on Rh/SnO2-C was almost 5-fold higher than on Rh/C, as demonstrated by electrochemical measurements in alkaline medium. This trend indicated the beneficial effect of the SnO2-C carbon-oxide composite support in the catalyst composition. Analysis of the products generated after the bulk electrolysis using high-performance liquid chromatography (HPLC) and FTIRS demonstrated that at 0.55 V vs RHE the main reaction products were glycerate ion and carbonate (CO3 2−). Then, a C–C–C cleavage was demonstrated with the CO3 2− formation at low potentials. During the testings conducted in a home-made acrylic direct glycerol fuel cell at room temperature in 0.5 mol l−1 NaOH, the maximum power density (390 μW cm−2) obtained on a Rh/SnO2 anode, was 5-fold higher than that on Pd/C. These testings demonstrated that the co-generation of sustainable energy and value-added products is a promising way to valorize glycerol.

An electrocatalyst with Cu nanoparticles embedded in a mesoporous carbon was prepared by the soft-template route using a green process. Its particular structure boosts its performance for CO2RR regarding selectivity and charge/mass transfers.

Solid-oxide fuel cells (SOFC) made of conventional materials with coplanar interdigitated electrodes located on the same side of the electrolyte have been fabricated and tested in a uniform mixture of methane and air in order to evaluate the influence of various operating parameters on cell performances. Anode thickness of several hundred micrometers is required to reach good cell stability. Also, the relative positioning of the electrodes in regard to the gas flow should be optimized as the gas composition is modified after passage over the anode. This aspect is particularly important with stacked cells, due to the modification of the gas composition in the upstream portion of the stack. Enhanced performances of the single-side cell were obtained by decreasing the width of the electrodes and their spacing, which both have the effect of reducing the ohmic loss. Following this approach, performances of 40 mW cm -2 were recorded at 800°C using electrodes of 0.5 X 8 mm separated by a gap of 0.2 mm.

Non-conventional online monitoring tools enable identification of the degradation in solid oxide fuel cells at its preliminary stage.

Single-chamber cells of two different types have been operated between 700 and 800°C in various methane-air mixtures. These cells are made mostly of conventional materials for solid oxide fuel cells (SOFCs), strontium-doped lanthanum manganite, yttria-stabilized zirconia (YSZ), and Ni-YSZ cermet. One type is electrolyte-supported, while the other represents a state-of-the-art fabrication for anode-supported cells. The anode-supported cells operate in a narrower range of methane-air ratios, but offer remarkable maximum specific powers, 360 and 285 mW/cm 2 at 800 and 700°C, respectively. Some theoretical considerations about the actual operation of these cells are also provided.

AbstractThe selective electrochemical conversion of highly functionalized organic molecules into electricity, heat, and added‐value chemicals for fine chemistry requires the development of highly selective, durable, and low‐cost catalysts. Here, we propose an approach to make catalysts that can convert carbohydrates into chemicals selectively and produce electrical power and recoverable heat. A 100 % Faradaic yield was achieved for the selective oxidation of the anomeric carbon of glucose and its related carbohydrates (C1‐position) without any function protection. Furthermore, the direct glucose fuel cell (DGFC) enables an open‐circuit voltage of 1.1 V in 0.5 m NaOH to be reached, a record. The optimized DGFC delivers an outstanding output power Pmax=2 mW cm−2 with the selective conversion of 0.3 m glucose, which is of great interest for cogeneration. The purified reaction product will serve as a raw material in various industries, which thereby reduces the cost of the whole sustainable process.

In single-chamber solid oxide fuel cells (SC-SOFCs), both anode and cathode are situated in a common gas chamber and are exposed to a mixture of fuel and oxidant. The working principle is based on the difference in catalytic activity of the electrodes for the respective anodic and cathodic reactions. The resulting difference in oxygen partial pressure between the electrodes leads to the generation of an open circuit voltage. Progress in SC-SOFC technology has enabled the generation of power outputs comparable to those of conventional SOFCs. This paper provides a detailed review of the development of SC-SOFC technology.

Abstract Anode catalysts synthesized by the thermal decomposition method were used for splitting water in PEM electrolysis cells. Although the area resistance of the ternary anode materials increased, the Ti content in the ruthenium and iridium based catalysts have led to an energy consumption of 4.5 kWh/Nm3(H2) at 60 °C. The Membrane Electrode Assemblies have given information on the strong dependence of the membrane thickness. The crossover of hydrogen through Nafion®117 is two-fold lower than that measured in the presence of Nafion®115. Life testing was attempted with supplying the electrolyzer by solar power source. Importantly, the proton exchange membrane water electrolyzer (PEMWE) cell has involved a constant cell voltage at 1 A cm−2 over 800 h durability tests.