Electrochemical transformation of limestone into calcium hydroxide and valuable carbonaceous products for decarbonizing cement production.

The cement industry is one of the largest contributors to global CO emissions, which has been paid more attention to the research on converting the CO released by the cement production process. It is extremely challenging to decarbonize the cement industry, as most CO emissions result from the calcination of limestone (CaCO) into CaO and CO. In this work, we demonstrate an electrochemical process that transforms CaCO into portlandite (Ca(OH), a key Portland cement precursor) and valuable carbonaceous products, which integrates electrochemical water splitting and CO reduction reaction with the chemical decomposition of CaCO. With different metal catalyst electrodes (like Au, Ag, In, Cu, and Cu nanowires electrodes), we have achieved various valuable carbonaceous products, such as CO, formate, methane, ethylene, and ethane during the electrochemical CO process. Our work demonstrates a proof of concept for green and sustainable cement production.