Sulfur-Doped Millimeter-Sized Microporous Activated Carbon Spheres Derived from Sulfonated Poly(styrene–divinylbenzene) for CO2 Capture

Abstract

Millimeter-sized activated carbon spheres are potential candidates for industrial-scale CO2 capture. Millimeter-sized sulfur-doped microporous activated carbon spheres were synthesized from poly(styrene–divinylbenzene), a very cheap and easily operated resin product, in the present work and studied for CO2 uptake. A series of sulfur-doped spherical carbon materials were yielded through the sulfonation, oxidation, carbonization, and KOH activation of the polymer precursors. In addition to promoting the cross-linking of the polymer molecules, the sulfonic substituents directly introduced sulfur functional groups into the carbon materials after pyrolysis. The SCS-700 sample showed the best CO2 adsorption performance, whose sulfur content reached 0.69 wt %, and exhibited a high surface area of 1526 m2 g–1 and a large pore volume of 0.726 cm3 g–1. The adsorbent showed high CO2 uptake at both 25 °C (4.21 mmol g–1) and 50 °C (2.54 mmol g–1) under ambient pressure due to its abundant ultramicropores and a high pr...