Development of metal-organic framework-based systems for H2S removal: A comprehensive review

Biogas is recognized as a source of renewable energy that can substitute for fossil fuels, especially natural gas. Biogas is produced from various organic resources, and it contains mainly methane (CH 4 ) and carbon dioxide (CO 2 ). However, several contaminants are found in the biogas flow such as hydrogen sulfide (H 2 S), water (H 2 O), ammonia (NH 3 ), and volatile organic compounds (VOCs). Therein, due to its high corrosion, toxicity, and bad odor, H 2 S must be eliminated first and intensively to avoid equipment damage and health risks. Among H 2 S removal technologies, using the solid adsorbent is viewed as a friendly and effective way. Recently, metal-organic frameworks (MOFs) have been studied with increasing attention for H 2 S adsorption thanks to their high surface area, good thermal stability and structural tunability. Although many MOFs-based systems have been designed for H 2 S removal, an intensive study to summarize them is missing. This work aims to revise the development of MOFs-based networks for H 2 S removal in literature including pristine MOFs, functionalized MOFs, MOF composites, and mixed-metal MOFs. We focus on explaining H 2 S adsorption mechanism of MOFs, and material engineering factors that directly affect the H 2 S adsorption capacity, the selectivity over other gases, and the ability to regenerate. Furthermore, several perspectives to enhance the removal performance of MOFs are also proposed. Together, this study will provide a comprehensive document on current technologies and perspective development of MOF-derived H 2 S adsorbent. • MOF-based materials for H 2 S removal are summarized and analyzed. • Impacts of material characteristics and operating conditions on H 2 S adsorption are discussed. • The comparison among MOF systems is systematically presented. • Challenges and future studies on MOF materials for H 2 S removal are proposed.