Synergistic Tuning of Structure and Active Phases in Zn-Mn Loaded Carbon Nanofiber Aerogel for High-Efficiency...

Hydrogen sulfide removal under mid-to-high temperature is one of the key technologies for the clean development of coal-based syngas, and its core lies in the design and development of sorbents with high active component utilization. Thus, a novel zinc-manganese composite sorbent supported on three-dimensional carbon nanofiber aerogels (Zn-MnCAs) is proposed to synergistically enhance the desulfurization efficiency through structural design and active phase regulation. The carbon nanofiber aerogel supporter possesses a dual-interpenetrating network structure, high porosity (>99%), and excellent anti-shrinkage properties. Its three-dimensional and open-pore structure significantly promotes gas mass transfer, with a permeability 28 times higher than that of traditional nanofiber membranes. Meanwhile, the loading content of MnO₂ and its desulfurization performance are remarkably improved after redox reaction. On this basis, by further optimizing the zinc salt concentration in the hydrothermal solution, the Zn-MnCAs sorbent exhibits outstanding performance in desulfurization evaluation, achieving a sulfur capacity of 10.3 g S/100 g sorbent and a zinc utilization rate as high as 91.1%. In situ XRD, EXAFS, and DFT calculations reveal that the presence of highly dispersed and abundant ZnO is the main reason for the enhanced performance. This work provides a new material design concept for developing desulfurization sorbents with high performance.