Preparation of Nitrogen-Doped Porous Carbon from Waste Polyurethane Foam by Hydrothermal Carbonization for H<sub>2</sub>S Adsorption
Wenhua Chen, Guocheng Zhang, Dan Li, Shenggui Ma, Bangda Wang, Xia Jiang
Abstract
In this work, we reported a nitrogen-doped porous carbon (NPC) that was prepared from waste polyurethane (PU) foams through hydrothermal carbonization and further activation. The possible reactions occurred during the hydrothermal carbonation and activation process of waste PU were proposed based on the results of gas chromatography–mass spectrometry and thermogravimetric Fourier transform infrared. Hydrothermal carbonization significantly improved the porous structure and surface N-containing active groups on carbon. The specific surface area and the total pore volume were obtained at 1419 m2/g and 0.80 cm3/g, respectively, for porous carbon prepared under 200 °C for 6 h, which were much higher than those without hydrothermal carbonization (1100 m2/g and 0.66 cm3/g). Moreover, the nitrogen contents on the porous carbon increased from 1.4 to 2.8 wt % with the majority of pyridinic and pyrrolic N species. The saturated sulfur capacity of NPC reached as high as 205.06 mg/g, which was almost 2.5 times higher than that without hydrothermal carbonization. The desulfurization performance could be tightly related to the hierarchical porous structure and active nitrogen species on the carbon induced by hydrothermal carbonization/catalysis. Thus, our current efforts provide a facile strategy for the preparation of porous adsorbent for H2S removal with the low cost and high efficiency.