Luo Huafeng, Qiao Yuandong, Ning Zhangxuan, Bo Chunli, Hu Jinguo
Coal Engineering College, Shanxi Datong University, Datong 037003, Shanxi, China.
ACS Omega. 2020 Jan 29;5(5):2465-2472. doi: 10.1021/acsomega.9b04044. eCollection 2020 Feb 11.
After coal is treated by thermal solution of solvent, a certain amount of thermal solution oil and residue can be obtained, and the macromolecular network structure in coal can also be relaxed. These will inevitably affect the emission of harmful gases and distribution of the pore structure when the residue is made into activated carbon (AC). In this paper, the effects of thermal solution pretreatment on the microcrystalline structure, surface properties, pore structure of resultant ACs at different temperatures, and their catalytic performances in methane decomposition to hydrogen were investigated. The results show that the surface oxygen-containing functional groups of the residue-based ACs are changed, and the specific area of ACs increases from 1730 to 2652 m/g with the increase in activated temperature. The pore diameter distribution of ACs also is changed. In the process of methane decomposition to hydrogen, the residue-based ACs show higher catalytic activity than coal-based ACs. AC-1123-1 and AC-1123 show the best stability, while AC-823-1 has the highest initial activity. With the increase in activated temperature, residue-based ACs show higher activity and stability, and partial fibrous carbon is deposited on the surface of ACs after the reaction. It is thought that increased mesoporosity is beneficial to the catalytic activity and stability of AC in methane decomposition to hydrogen, and the reduction of surface oxygen-containing functional groups contribute to the formation of fibrous carbon on the surface of AC after the reaction.
煤经溶剂热溶处理后，可得到一定量的热溶油和残渣，煤中的大分子网络结构也会得到松弛。当将残渣制成活性炭（AC）时，这些情况将不可避免地影响有害气体的排放和孔隙结构的分布。本文研究了热溶预处理对不同温度下所得活性炭微晶结构、表面性质、孔隙结构及其在甲烷分解制氢中的催化性能的影响。结果表明，残渣基活性炭的表面含氧官能团发生了变化，随着活化温度的升高，活性炭的比表面积从1730增加到2652 m/g。活性炭的孔径分布也发生了变化。在甲烷分解制氢过程中，残渣基活性炭比煤基活性炭表现出更高的催化活性。AC-1123-1和AC-1123表现出最佳的稳定性，而AC-823-1具有最高的初始活性。随着活化温度的升高，残渣基活性炭表现出更高的活性和稳定性，反应后活性炭表面有部分纤维状碳沉积。研究认为，介孔率的增加有利于活性炭在甲烷分解制氢中的催化活性和稳定性，表面含氧官能团的减少有助于反应后活性炭表面纤维状碳的形成。
