Abstract:Mercury, as a widespread heavy metal pollutant, poses a serious threat to both human health and the ecosystem. It is of great significance to develop efficient mercury removal technology for decreasing elemental mercury (Hg0） emissions from flue gas and controlling atmospheric mercury pollution. Adsorption has emerged as a simple, practical, and promising method for mercury removal, and various types of adsorbents for Hg0 removal have been developed for the efficient adsorption and recovery of Hg0 from flue gas. In this work, we systematically classified adsorbents based on their effective components, provided an in-depth examination of their characteristics of preparation methods, Hg0 removal performance, and adsorption mechanisms. Furthermore, we conducted a thorough analysis and comparison of these materials across multiple dimensions, examining their performance and characteristics. Adsorbents for mercury removal can be broadly categorized into four main types: carbon-based and modified materials, metal oxides, metal sulfides, and other innovative materials. Carbon-based and modified materials are particularly effective in removing Hg0 due to a large specific surface area and the presence of various functional groups, such as C—O, C—NO, C—S, C—Cl. However, these adsorbents suffer from limitations such as poor heat resistance, deficient functional groups, and as a result exhibit small adsorption capacities, poor stability, and recyclability. Metal oxide adsorbents are primarily composed of iron and manganese oxides, forming various crystal structures. These adsorbents stand out for their operational stability across a broad temperature range, from room temperature up to 250 ℃, and their large adsorption capacities. Moreover, they benefit from the thermal stability, and maintain their effectiveness over multiple cycles. Metal sulfide adsorbents primarily rely on the abundant unsaturated S-sites to achieve efficient adsorption of Hg0. Their advantages include high activity, wide operational temperature range, and large adsorption capacities, but the high temperatures required for thermal regeneration can easily degrade their activity, resulting in challenges in recyclability. Based on the above analysis and summary of the characteristics and research progress on adsorbents, the respective advantages and disadvantages of different types of adsorbents are illustrated, and targeted development suggestions are proposed. This work provides novel ideas and valuable references for the development of new materials, as well as their potential and further application in mercury removal technology through adsorption. Close-