Zhang Guanqing, Zhu Qiliang, Zhang Wentao, Zheng Yong, Cao Yanning, Liang Shijing, Xiao Yihong, Liu Fujian, Jiang Lilong
National Engineering Research Center of Chemical Fertilizer Catalyst, College of Chemical Engineering, Fuzhou University, Fuzhou, Fujian 350002, P.R. China.
Qingyuan Innovation Laboratory, Quanzhou, Fujian 362801, P.R. China.
Inorg Chem. 2022 Apr 25;61(16):6083-6093. doi: 10.1021/acs.inorgchem.2c00149. Epub 2022 Apr 11.
Selective removal of carbonyl sulfide (COS) and hydrogen sulfide (HS) is the key step for natural gas desulfurization due to the highly toxic and corrosive features of these gaseous sulfides, and efficient and stable desulfurizers are urgently needed in the industry. Herein, we report a class of nitrogen-functionalized, hierarchically lamellar carbon frameworks (N-HLCF-xs), which are obtained from the structural transformation of Zn zeolitic imidazolate frameworks via controllable carbonization. The N-HLCF-xs possess the desirable characteristics of large Brunauer-Emmett-Teller surface areas (645-923 m/g), combined primary three-dimensional microporosity and secondary two-dimensional lamellar microstructure, and high density of nitrogen base sites with enhanced pyridine ratio (17.52 wt %, 59.91%). The anchored nitrogen base sites in N-HLCF-xs show improved accessibility, which boosts their interaction with acidic COS and HS. As expected, N-HLCF-xs can be employed as multifunctional and efficient desulfurizers for selective removal of COS and HS from natural gas. COS was first transformed into HS via catalytic hydrolysis, and the produced HS was then captured and separated and catalyzed oxidation into elemental sulfur. The above continuous processes can be achieved with solo N-HLCF-xs, giving extremely high efficiencies and reusability. Their integrated desulfurization performance was better than many desulfurizers used in the area, such as activated carbon, β zeolite, MIL-101(Fe), KCO/γ-AlO, and FeO/TiO.
由于羰基硫（COS）和硫化氢（H₂S）具有高毒性和腐蚀性，选择性脱除它们是天然气脱硫的关键步骤，工业上迫切需要高效稳定的脱硫剂。在此，我们报道了一类氮功能化的分级层状碳骨架（N-HLCF-xs），它是通过对锌沸石咪唑酯骨架进行可控碳化，由其结构转变得到的。N-HLCF-xs具有理想的特性，如较大的比表面积（645 - 923 m²/g）、兼具的一级三维微孔结构和二级二维层状微观结构，以及吡啶比提高（17.52 wt%，59.91%）的高密度氮碱位点。N-HLCF-xs中锚定的氮碱位点具有更好的可及性，增强了它们与酸性COS和H₂S的相互作用。正如预期的那样，N-HLCF-xs可作为多功能高效脱硫剂，用于从天然气中选择性脱除COS和H₂S。COS首先通过催化水解转化为H₂S，然后生成的H₂S被捕获、分离并催化氧化为单质硫。上述连续过程仅用N-HLCF-xs就能实现，具有极高的效率和可重复使用性。它们的综合脱硫性能优于该领域使用的许多脱硫剂，如活性炭、β沸石、MIL-101(Fe)、K₂CO₃/γ-Al₂O₃和Fe₂O₃/TiO₂ 。
