In a world powered by intermittent renewable energy, electrolyzers will play a central role in converting electrical energy into chemical energy, thereby decoupling the production of transport fuels and chemicals from today’s fossil resources and decreasing the reliance on bioenergy. Solid oxide electrolysis cells (SOECs) offer two major advantages over alternative electrolysis technologies. First, their high operating temperatures result in favorable thermodynamics and reaction kinetics, enabling unrivaled conversion efficiencies. Second, SOECs can be thermally integrated with downstream chemical syntheses, such as the production of methanol, dimethyl ether, synthetic fuels, or ammonia. SOEC technology has witnessed tremendous improvements during the past 10 to 15 years and is approaching maturity, driven by advances at the cell, stack, and system levels.

Recently, the field of CO2 electrolysis has experienced rapid scientific and technological progress. This review focuses specifically on the electrochemical conversion of CO2 into carbon monoxide (CO), an important “building block” for the chemicals industry. CO2 electrolysis technologies offer potentially carbon-neutral routes for the production of specialty and commodity chemicals. Many different technologies are actively being pursued. Electrochemical CO2 reduction from aqueous solutions stems from the success of alkaline and polymer electrolyte membrane electrolyzers for water electrolysis and uses performance metrics established within the field of aqueous electrochemistry. High-temperature CO2 electrolysis systems rely heavily on experience gained from developing molten carbonate and solid oxide fuel cells, where device performance is evaluated using very different parameters, commonly employed in solid-state electrochemistry. In this review, state-of-the-art low-temperature, molten carbonate, and solid oxide electrolyzers for the production of CO are reviewed, followed by a direct comparison of the three technologies using some of the most common figures of merit from each field. Based on the comparison, high-temperature electrolysis of CO2 in solid oxide electrolysis cells seems to be a particularly attractive method for electrochemical CO production, owing to its high efficiency and proven durability, even at commercially relevant current densities.

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A series of electrochemical impedance experiments has been carried out in order to investigate the effect of cell composition and geometry on the determination of electrochemical characteristics of strontium-doped lanthanum cobaltite ͑La 0.6 Sr 0.4 CoO 3−␦ ͒ cathodes. The impedance responses at different electrode potentials of the half-cell and symmetric single-cell setups are compared and analyzed by the equivalent circuit modeling method. The deconvolution of impedance spectra for single cells has been achieved by a differential impedance real part vs ac frequency plot analysis method. The results indicate that the three-electrode half-cell configuration is more suitable for fundamental research of material parameters at different electrode potentials ͑measured vs Pt͉O 2 reference electrode͒, whereas the simpler two-electrode single-cell setup allows the estimation of cathode performance in approximate working conditions. Solid oxide fuel cells ͑SOFCs͒ are considered as one of the most promising systems for energy conversion in the near future due to their very high electrical efficiency and the possibility to operate with lower or zero emissions. 1 However, wider use of SOFC technology is restrained by high material costs and long-term durability problems. Both of these challenges have been addressed quite successfully over recent years by the introduction of the so-called intermediate-temperature SOFC ͑IT-SOFC͒ concept. 2-12 IT-SOFCs make use of low-temperature ionic conductors, such as gadoliniadoped ceria ͓Ce 0.9 Gd 0.1 O 2−␦ , ͑CGO͔͒ or samaria-doped ceria ͑Ce 0.9 Sm 0.1 O 2−␦ ͒ instead of the traditional yttria-stabilized zirconia, thus allowing reducing the operating temperature of the cell to below 800°C. 2 Such a temperature reduction greatly enhances the long-term stability of the fuel cell, as the rate of electrochemical corrosion of construction details and current collectors decreases exponentially with temperature. Equally important, lower operating temperatures allow cheaper materials, such as various stainless steels, to be employed as potential construction and current collection materials. Additionally, the issue of finding suitable sealing materials becomes less severe through fewer restrictions on the thermal expansion properties imposed. 1,2,13 One of the key issues in IT-SOFC research is the development of cathode materials that would possess high electrochemical activity toward the oxygen electroreduction process at reduced operation temperature. 3-12 La 0.6 Sr 0.4 CoO 3−␦ ͑LSCO͒ is a mixed ionic and electronic conductor of ABO 3 perovskite structure. As can be seen from Table I, the electronic conductivity of LSCO is much higher than that for Sr-doped LaMnO 3 , the cathode material most commonly used in high-temperature SOFCs. 1-13 The main concerns regarding the wider use of LSCO are the large thermal expansion mismatch with the CGO electrolyte, as well as the relatively low tolerance toward reducing environments. 1,5 Numerous papers on LSCO have been published over the recent years, 3...

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Data sharing is one of the cornerstones of modern science that enables large-scale analyses and reproducibility. We evaluated data availability in research articles across nine disciplines in Nature and Science magazines and recorded corresponding authors’ concerns, requests and reasons for declining data sharing. Although data sharing has improved in the last decade and particularly in recent years, data availability and willingness to share data still differ greatly among disciplines. We observed that statements of data availability upon (reasonable) request are inefficient and should not be allowed by journals. To improve data sharing at the time of manuscript acceptance, researchers should be better motivated to release their data with real benefits such as recognition, or bonus points in grant and job applications. We recommend that data management costs should be covered by funding agencies; publicly available research data ought to be included in the evaluation of applications; and surveillance of data sharing should be enforced by both academic publishers and funders. These cross-discipline survey data are available from the plutoF repository.

Atomic layer deposition (ALD) offers exciting possibilities for controlling the structure and composition of surfaces on the atomic scale in heterogeneous catalysts and solid oxide fuel cell (SOFC) electrodes. However, while ALD procedures and equipment are well developed for applications involving flat surfaces, the conditions required for ALD in porous materials with a large surface area need to be very different. The materials (e.g., rare earths and other functional oxides) that are of interest for catalytic applications will also be different. For flat surfaces, rapid cycling, enabled by high carrier-gas flow rates, is necessary in order to rapidly grow thicker films. By contrast, ALD films in porous materials rarely need to be more than 1 nm thick. The elimination of diffusion gradients, efficient use of precursors, and ligand removal with less reactive precursors are the major factors that need to be controlled. In this review, criteria will be outlined for the successful use of ALD in porous materials. Examples of opportunities for using ALD to modify heterogeneous catalysts and SOFC electrodes will be given.