Effects of Iron Species on Low Temperature CO2 Electrolyzers

Electrochemical energy conversion devices are considered key in reducing CO2 emissions and significant efforts are being applied to accelerate device development. Unlike other technologies, low temperature electrolyzers have the ability to directly convert CO2 into a range of value‐added chemicals. To make them commercially viable, however, device efficiency and durability must be increased. Although their design is similar to more mature water electrolyzers and fuel cells, new cell concepts and components are needed. Due to the complexity of the system, singular component optimization is common. As a result, the component interplay is often overlooked. The influence of Fe‐species clearly shows that the cell must be considered holistically during optimization, to avoid future issues due to component interference or cross‐contamination. Fe‐impurities are ubiquitous, and their influence on single components is well‐researched. The activity of non‐noble anodes has been increased through the deliberate addition of iron. At the same time, however, Fe‐species accelerate cathode and membrane degradation. Here, we interpret literature on single components to gain an understanding of how Fe‐species influence low temperature CO2 electrolyzers holistically. The role of Fe‐species serves to highlight the need for considerations regarding component interplay in general

Stable carbon and nitrogen isotopes identify nuanced dietary changes from the Bronze and Iron Ages on the Great Hungarian Plain

The Great Hungarian Plain (GHP) served as a geographic funnel for population mobility throughout prehistory. Genomic and isotopic research demonstrates non-linear genetic turnover and technological shifts between the Copper and Iron Ages of the GHP, which influenced the dietary strategies of numerous cultures that intermixed and overlapped through time. Given the complexities of these prehistoric cultural and demographic processes, this study aims to identify and elucidate diachronic and culture-specific dietary signatures. We report on stable carbon and nitrogen isotope ratios from 74 individuals from nineteen sites in the GHP dating to a ~ 3000-year time span between the Early Bronze and Early Iron Ages. The samples broadly indicate a terrestrial C 3 diet with nuanced differences amongst populations and through time, suggesting exogenous influences that manifested in subsistence strategies. Slightly elevated δ 15 N values for Bronze Age samples imply higher reliance on protein than in the Iron Age. Interestingly, the Füzesabony have carbon values typical of C 4 vegetation indicating millet consumption, or that of a grain with comparable δ 13 C ratios, which corroborates evidence from outside the GHP for its early cultivation during the Middle Bronze Age. Finally, our results also suggest locally diverse subsistence economies for GHP Scythians

The Beaker phenomenon and the genomic transformation of northwest Europe

From around 2750 to 2500 bc, Bell Beaker pottery became widespread across western and central Europe, before it disappeared between 2200 and 1800 bc. The forces that propelled its expansion are a matter of long-standing debate, and there is support for both cultural diffusion and migration having a role in this process. Here we present genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 individuals associated with Beaker-complex artefacts. We detected limited genetic affinity between Beaker-complex-associated individuals from Iberia and central Europe, and thus exclude migration as an important mechanism of spread between these two regions. However, migration had a key role in the further dissemination of the Beaker complex. We document this phenomenon most clearly in Britain, where the spread of the Beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain’s gene pool within a few hundred years, continuing the east-to-west expansion that had brought steppe-related ancestry into central and northern Europe over the previous centuries

Early Bronze Age headdress markers of the social status in the Bell Beaker-Csepel Group

Ten out of the uncovered 155 burials of the Early Bronze Age Bell Beaker–Csepel Group at Szigetszentmiklós-Üdülősor had circular ditches. The largest circular ditch of the cemetery enclosed a grave with scattered ashes and two symbolic graves. The central burial of a man contained “prestige goods”: silver/electron plate ornaments. According to our hypothetical reconstruction, it was a headdress worn as a diadem fixed on some organic material. The special symbolic phenomena and the complexity of the grave goods indicate the social status of the buried individual. | <p/

Symbolism and traditions in the society of the Bell Beaker - Csepel group

In the present paper, we called attention to a so far unknown religious idea of the Bell Beaker - Csepel group after observations made at the excavation of Budapest-Albertfalva, archaeo-astronomical analyses, two special shards with channelled knob ornaments and their analogues. The schematic representation of the Sun symbol appears, although rarely, in the accompanying material (“Begleitkeramik”) of the Csepel group (on grave ceramics, the Albertfalva fragment was probably originally intended to be placed in a grave). The custom of the building of round houses in the western group of the Bell Beaker culture and the burials with round ditches in the eastern group make us think. The orientation of the houses according to the winter solstice at Albertfalva and the existence of a territory enclosed by a round ditch between the houses render the role of the Sun in the daily and religious life of the population of the Csepel group even more emphatic. The representation of the Sun in various forms (gold discs, incised Sun motives) can be observed on nearly the entire territory of the Bell Beaker culture yet we do not want to interpret this phenomenon as a Sun cult. The religious beliefs of the Bell Beaker culture are extremely complicated, complex and colourful, and Sun, an environmental factor that defines daily life, could only be an element in it

Photo/electrocatalytic hydrogen exploitation for CO2 reduction toward solar fuels production

This chapter discusses the transformation of CO2 to value-added products, with a focus on the exploitation of sun-driven water splitting for generation of hydrogen protons (H+) that can be used in situ for the CO2 reduction reaction. It starts by introducing CO2 as a raw material for the production of fuels or chemicals by conventional (thermocatalytic) conversion processes or emerging sun-driven technologies. It then gives a background about the different figures of merit that must be considered and identifies the opportunities for syngas production. Different architectures for syngas production are presented, considering the photo-driven systems and with particular emphasis on the electrochemical systems. It proceeds by extensively discussing various catalysts for these two kinds of systems. Finally, it tackles the promising solvent-less route for the electrochemical conversion of CO2 to value-added products