Stimuli-responsive Adsorbents for Selective Separation of Sulfur Compounds

The selective removal of sulfur-containing compounds from fuels and industrial gas streams is a critical challenge for environmental compliance, catalyst protection, and fuel quality enhancement. Conventional adsorbents often lack specificity, recyclability, or tunable selectivity, motivating the development of stimuli-responsive (smart) adsorbents that dynamically adapt their surface chemistry and pore accessibility in response to external triggers such as pH, temperature, light, or chemical stimuli. This review provides a comprehensive and critical analysis of the recent advances in stimuli-responsive adsorbent materials for the selective capture of thiols, sulfides, and other organosulfur species. We focus on design strategies and functional mechanisms, highlighting the role of polymeric networks, biopolymer composites, metal-functionalized mesoporous frameworks, and hybrid smart materials. The review emphasizes how multi-stimuli responsiveness-combining thermal, pH, and photo-triggered functionalities-enables tunable adsorption selectivity, enhanced capacity, and facile regeneration. Mechanistic insights reveal that adsorption is governed by a combination of physisorption in microporous domains and chemisorption via reactive surface moieties, with selectivity strongly modulated by functional group density, molecular recognition sites, and responsive conformational changes in polymeric matrices. Recent studies demonstrate that stimuli-responsive materials can achieve reversible and high-capacity sulfur capture, allowing for multiple adsorption-desorption cycles with minimal performance loss. Integration of computational modeling, molecular simulations, and experimental characterization has provided predictive design rules for optimizing adsorbent architecture and responsiveness. Furthermore, the incorporation of sustainable and renewable precursors, including polysaccharides and biomass-derived polymers, aligns with green chemistry principles and reduces environmental impact. Overall, stimuli-responsive adsorbents represent a promising platform for next-generation smart desulfurization technologies, offering a pathway toward highly selective, recyclable, and tunable sulfur removal in complex gas streams. Future research should focus on scalable synthesis, multi-stimuli integration, and process-level validation to enable industrial adoption and practical applications.

کلیدواژه ها:

Stimuli-Responsive Adsorbents ، Smart Materials ، Thiols and Sulfides ، Hybrid Smart Adsorbents ، Tunable Selectivity ، Desulfurization Technology