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

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.