Bimetallic-MOF-Derived ZnxCo3–xO4/Carbon Nanofiber Composited Sorbents for High-Temperature Coal Gas Desulfurization

Desulfurization sorbent with a high active component utilization is of importance for the removal of H₂S from coal gas at high temperatures. Thus, the hypothesis for producing Zn_xCo_3-xO₄/carbon nanofiber sorbents via the combinations of electrospinning, in situ hydrothermal growth, and carbonization technique has been rationally constructed in this study. Zn_xCo_3-xO₄ nanoparticles derived from metal-organic frameworks are uniformly loaded on the electrospun carbon nanofibers (CNFs) with high dispersion. Zn_xCo_3-xO₄/CNFs sorbents possess the highest breakthrough sulfur adsorption capacity (12.4 g S/100 g sorbent) and an excellent utilization rate of the active component (83.2%). The excellent performance of Zn_xCo_3-xO₄/CNFs can be attributed to the synergetic effect of the hierarchical structure and widely distributed Zn_xCo_3-xO₄ on the CNFs supporter. The decomposition of Zn/Co-ZIFs not only generates the nucleus of oxides but also realizes their physical isolation through the formation of carbon grids on the surface of CNFs, avoiding the aggregation of oxides. Furthermore, Zn_xCo_3-xO₄/CNFs sorbents show an overwhelming superiority over the ZnO/CNFs sorbent, which is attributed to the introduction of Co and then the promotion of the stability of Zn at high temperatures. The presence of Co also accelerates the adsorption of H₂S on the active site of the oxide surface. The presented method is beneficial for promoting desulfurization performances and producing sorbents with high utilization of active components.