Influence of Support Material on the Structural Evolution of Copper during Electrochemical CO2 Reduction

The copper-catalyzed electrochemical CO2 reduction reaction represents an elegant pathway to reduce CO2 emissions while producing a wide range of valuable hydrocarbons. The selectivity for these products depends strongly on the structure and morphology of the copper catalyst. However, continued deactivation during catalysis alters the obtained product spectrum. In this work, we report on the stabilizing effect of three different carbon supports with unique pore structures. The influence of pore structure on stability and selectivity was examined by high-angle annular dark field scanning transmission electron microscopy and gas chromatography measurements in a micro-flow cell. Supporting particles into confined space was found to increase the barrier for particle agglomeration during 20 h of chronopotentiometry measurements at 100 mA cm−2 resembling long-term CO2 reduction conditions. We propose a catalyst design preventing coalescence and agglomeration in harsh electrochemical reaction conditions, exemplarily demonstrated for the electrocatalytic CO2 reduction. With this work, we provide important insights into the design of stable CO2 electrocatalysts that can potentially be applied to a wide range of applications

Iron supported on beaded carbon black as active, selective and stable catalyst for direct CO2 to olefin conversion

The Fischer-Tropsch-to-Olefins process allows to convert waste stemming CO2 with green hydrogen to olefins. Iron can catalyse both core reactions: 1) reverse-water-gas-shift as well as 2) Fischer-Tropsch. Carbon supported catalysts were reported to be highly attractive in this context, but until now mainly non technically applicable research carbons like nanotubes or ordered mesoporous carbons were studied and long term stability studies are missing. Here, beaded carbon blacks, were studied as available and inexpensive support materials for Fe catalysts in CO2-based FTO. The most promising support yielded selectivities towards olefins of almost 40% and showed for 170 h high stability

Unlocking the Potential of Sub‐Nanometer Pd Catalysts for Electrochemical Hydrogen Peroxide Production

Abstract The utilization of nanoscale catalysts represents a valuable and promising strategy for augmenting catalytic performance while mitigating the reliance on expensive noble metals. Nevertheless, a significant knowledge gap persists regarding the intricate interplay between catalyst size, physical properties, and catalytic behavior in the context of the oxygen reduction reaction. In this study, the synthesis of precisely controlled palladium catalysts is presented, spanning a wide range from individual atoms to metal clusters and nanoparticles, followed by a comprehensive evaluation of their performance in acidic conditions. The results show a significant increase in H2O2 selectivity of up to 96% with decreasing catalyst size and strategic approaches are identified to eliminate unselective sites, facilitating the attainment of active and selective catalysts. The enhanced selectivity of the catalysts highlights the potential of single atom catalytic sites and can be adapted to improve the performance of various catalytic processes