Researchers at (University of Bochum) University in Bochum and Duisburg-Essen University University in Duisburg-Essen have developed a new catalyst for converting carbon dioxide (CO2) into chemicals or fuels.
In a paper published in the journal Angewandte Chemie, the scientists explained that what they did was to optimize existing copper catalysts to improve their selectivity and long-term stability.
Even if copper has emerged as a promising catalyst, it must exist in the form of partially positively charged ions, according to the researchers. The problem is that under conventional reaction conditions, copper changes rapidly from its positively charged form to a neutral state, which is not conducive to the formation of products with more than two carbon atoms, thus deactivating the catalyst.
In order to solve this problem, the research team led by Song Yanfang modified the copper catalyst with boron. In detail, they tested different copper-boron ratios and determined the best composition to facilitate the formation of compounds with more than two carbon atoms. They also show that boron-copper catalysts can operate at the density required on an industrial scale.
Their experiments involve the implementation of a system in the form of a gas diffusion electrode in which a solid catalyst catalyzes an electrochemical reaction between the liquid phase and the gas phase. In the boundaries of these stages, CO 2 should be dissolved, and the team was able to use special adhesives to achieve this goal.
In addition, in order to prevent electrode corrosion and keep the system stable for a long time, chemists integrated a so-called "sacrificial anode" made of zinc into the system. Because zinc is a sub-precious metal relative to copper, zinc is corroded first while retaining copper.
Wolfgang Schumann (Wolfgang Schuhmann), co-author of the study, said: "combining selective and active catalyst materials with stable zinc in a gas diffusion electrode is an important step towards the use of CO2 to synthesize basic chemicals."
