关键词: 二氧化碳捕集, 电解, 二氧化硅, 电化学, 催化剂, 二氧化碳减排

Abstract:

The large amount of CO₂ emitted by the burning of fossil fuels contributes to global climate warming. CO₂ mineralization is one of the most effective technologies for CO₂ terminal emission reduction in recent years. CO₂ mineralization can use natural alkaline minerals or industrial alkaline solid waste for transforming acidic CO₂ gas into carbonate. Despite its promise, many reported CO₂ mineralization methods remain plagued by excessive energy consumption and cost. This study introduces an innovative, environmentally friendly, and energy-efficient air-driven membrane electrolysis technology, tailored for efficient CO₂ mineralization and the production of high-quality porous silica materials. The key advancement of this technology hinges on the simultaneous occurrence of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) at the anode and cathode, respectively, within the electrolytic environment. This unique feature results in low-energy water ionization, generating both alkaline and acidic solutions. Crucially, this developed electrolytic technology demonstrates a substantial reduction in electrolytic voltage, at least 0.5 V lower than conventional electrolytic processes under equivalent current densities. By combining the acidic solution from the anode with a moderately alkaline solution from the cathode to dissolve wollastonite, the resultant mixture yields high-quality porous silica. Subsequently, the filtrate and remaining alkaline solution at the cathode effectively absorb CO₂, yielding calcium carbonate as the mineralization product. This breakthrough technology offers a compelling pathway to efficient CO₂ utilization through mineralization, addressing both environmental concerns and energy efficiency challenges.

Key words: CO₂ capture, electrolysis, silica, electrochemistry, catalyst, CO₂ emission reduction