Title : Electrocatalytic refinery to decarbonize and decentralize hydrogen peroxide and ammonia production
Access to green, flexible and reliable energy and chemicals is the key to global sustainable development and increasing prosperity, especially in the post-COVID-19 and carbon-neutral economy. Aiming at creating changes in energy technologies and chemicals manufacturing, we proposed the electrocatalytic refinery (e-refinery) to defossilize, decarbonize and decentralize present chemical industry. We for the first time established the concept, principles, and methodologies of e-refinery. Based on it, we aim to develop new technologies that can creatively produce some key chemicals (e.g., H2, hydrogen peroxide, ammonia, formate, urea) directly from abundant sources (e.g., water, air, CO2) and powered by renewable electricity.
Specifically, we developed an efficient e-refinery strategy for producing H2O2 directly from water and oxygen via two-electron oxygen reduction, which is of high flexibility to be operated in small scales and on demand. Our work innovatively engineers the structure of electrocatalysts at the molecular level, and has achieved present best activity and selectivity (> 95%) for H2O2 production in both alkaline and acidic conditions. The obtained concentration of H2O2 (> 1%) is high enough for practical applications such as disinfection and electro-Fenton water treatment. Besides, we also innovated the ammonia production technologies by electrocatalysis directly from air (N2 and O2) and water. We proposed for the first time bismuth catalysts for direct electrocatalytic nitrogen fixation into ammonia at ambient conditions. To address the significant drawbacks of tough N2 activation and poor NH3 selectivity, we developed a new two-step process through integration of plasma oxidation with electrocatalytic reduction, leading to ~2500 times higher yield and ~100% Faradaic efficiency. All the research in materials design and mechanism elucidation are achieved by combining atomic-level material engineering, electrochemical evaluation, theoretical computations, and advanced in situ characterizations.
Keywords: electrocatalysis, hydrogen peroxide, ammonia, single-atom catalysts.