Bimetallic-MOF-Derived Zn<sub><i>x</i></sub>Co<sub>3–<i>x</i></sub>O<sub>4</sub>/Carbon Nanofiber Composited Sorbents for High-Temperature Coal Gas Desulfurization
Ziwei Ru, Xin Zhang, Man Zhang, Jie Mi, Chunyan Cao, Zhifeng Yan, Mingzheng Ge, Hongchao Liu, Jiancheng Wang, Wei Zhang, Weilong Cai, Yuekun Lai, Yu Feng
Abstract
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 ZnxCo3–xO4/carbon nanofiber sorbents via the combinations of electrospinning, in situ hydrothermal growth, and carbonization technique has been rationally constructed in this study. ZnxCo3–xO4 nanoparticles derived from metal–organic frameworks are uniformly loaded on the electrospun carbon nanofibers (CNFs) with high dispersion. ZnxCo3–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 ZnxCo3–xO4/CNFs can be attributed to the synergetic effect of the hierarchical structure and widely distributed ZnxCo3–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, ZnxCo3–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.