چكيده به لاتين
Since the beginning of the Industrial Revolution, there has been an exceptional increase in pollution levels caused by industrial facilities, primarily due to the burning of fossil fuels (coal, crude oil, and natural gas). This has led to the generation of numerous pollutants, including nitrogen oxides (NOx), sulfur oxides (SOx), lead (Pb), carbon dioxide (CO₂), and others.
However, in recent years, serious concerns have arisen due to the significant increase in CO₂ concentration, which is one of the primary greenhouse gases. In 2020, the concentration of this gas in the atmosphere reached 414 ppm, the highest recorded level.
Although high concentrations of CO₂ can be harmful, its capture and utilization represent one of the most promising strategies for reducing CO₂ emissions and utilizing renewable resources. The adsorption of this gas has various applications, including the production of value-added chemicals and diverse products such as methanol, methane, cyclic carbonates, urea, acids, and more.
Currently, various materials are being studied for their ability to form appropriate adsorption interactions with CO₂, including activated carbon, zeolites, metal oxides, metal-organic frameworks (MOFs), amine-based materials, and mesoporous silicas (PMOs).
To overcome the challenges associated with conventional liquid amines, recent studies have focused on synthesizing solid adsorbents modified with amines. Since CO₂ is a gas and its reaction in the liquid phase requires overcoming a high energy barrier, CO₂ adsorption by solids has gained significant attention. Nanomaterials with porosity are particularly suitable for CO₂ adsorption. As a result, mesoporous silicas and periodic mesoporous organosilicas (PMOs) have been widely studied as solid adsorbents, with their adsorption properties enhanced by modification with amine-rich compounds [4].
The modification of porous silica adsorbents with amine groups offers several advantages, including ease of synthesis and low cost. However, a drawback of this technique is that the amines are often located on the surface of the porous solids rather than inside their pores, which can impact the optimal conditions for CO₂ adsorption.
To enhance CO₂ adsorption, organic bridges containing aniline-based segments will be utilized.
