The ongoing threat of global warming to both human society and ecological systems is primarily attributed to greenhouse gases, with carbon dioxide being the most significant contributor to climate warming. In the pursuit of addressing climate change and achieving carbon neutrality objectives, scientists from The Hong Kong Polytechnic University (PolyU) have created a resilient, highly selective, and energy-efficient electroreduction system for carbon dioxide (CO2). This system effectively transforms CO2 into ethylene for industrial applications, presenting a viable solution to mitigate CO2 emissions. The research, recently featured in Nature Energy, was honored with a Gold Medal at the 48th International Exhibition of Inventions in Geneva, Switzerland.
Ethylene (C2H4) stands out as a highly sought-after chemical on a global scale, primarily utilized in the production of polymers like polyethylene, a key material in manufacturing plastics and everyday items such as shopping bags. Despite its high demand, ethylene is predominantly sourced from petrochemical origins, contributing significantly to carbon emissions. Under the leadership of Prof. Daniel LAU, Chair Professor of Nanomaterials and Head of the Department of Applied Physics, the research team has embraced electrocatalytic CO2 reduction as a method, utilizing sustainable electricity to convert carbon dioxide into ethylene. This approach offers a more environmentally friendly and stable means of ethylene production. The team is actively working towards advancing this technology for widespread adoption, aiming to close the carbon loop and ultimately achieve carbon neutrality.
Prof. Lau's innovation involves eliminating the alkali-metal electrolyte and utilizing pure water as a metal-free anolyte to prevent the formation of carbonates and deposition of salts. The research team refers to their design as the APMA system, where A represents an anion-exchange membrane (AEM), P signifies the proton-exchange membrane (PEM), and MA denotes the resulting membrane assembly. Constructing a cell stack without alkali metals, incorporating the APMA and a copper electrocatalyst, resulted in ethylene production with a notable specificity of 50%.
