ABSTRACT: Although copper has become a promising catalyst, it must be in the form of partially positively charged ions, according to the researchers. The problem is that under conventional reaction conditions, copper would quickly change from a positively charged form to a neutral state, which would be detrimental to products with more than two carbon atoms, rendering the catalyst inoperative.

Researchers at Ruhr University Bochum and University of Duisburg-Essen have developed a new catalyst for converting carbon dioxide (CO2) into chemicals or fuels. In a paper published in the journal Angewandtechemie, the scientists explained that what they had done was to optimize existing copper catalysts to improve their selectivity and long-term stability.

Although copper has become a promising catalyst, it must appear as partially positively charged ions, according to the researchers. The problem is that under conventional reaction conditions, copper would quickly change from a positively charged form to a neutral state, which would be detrimental to products with more than two carbon atoms, rendering the catalyst inoperative.

To solve this problem, a team led by Yanfang Song modified the copper catalyst with Boron. Specifically, they tested different ratios of copper to Boron and determined the optimum composition for forming compounds with more than two carbon atoms. They also showed that the boron-copper catalyst could operate at the density required for industrial scale.

Their experiments involved implementing a Gas diffusion electrode system in which a solid catalyst catalyzes an electrochemical reaction between the liquid and gas phases. At the boundaries of these phases, carbon dioxide should dissolve, and the team was able to do this using a special adhesive.

In addition, to prevent corrosion of the electrodes and maintain long-term stability of the system, chemists have integrated a so-called "sacrificial anode" made of zinc into the system. Since zinc is a cheaper metal than copper, it is corroded first and copper is protected.

Wolfgang Schuhmann, Co author of the study, said in a media statement, "The combination of selective and active catalyst materials in the Gas diffusion electrode and the addition of stable zinc is an important step towards the use of carbon dioxide in the synthesis of basic chemicals

Source: Antek