Low Temperature Desulfurization of H₂S: High Sorption Capacities by Mesoporous Cobalt Oxide via Increased H₂S Diffusion

Mesoporous cobalt oxides (M-Co-X, X = 150, 250, 350, 450 °C) with tunable porosity and crystallinity were synthesized based on an inverse micelle soft template method. They are the members of recently discovered University of Connecticut (UCT) mesoporous materials. The M-Co-X materials were investigated as desulfurizing sorbents in a fixed bed reactor in the temperature range of 25–250 °C. A considerably high sulfur sorption capacity was observed even at room temperature (13.4 g S/100 g sorbent), and very high values were observed in the temperature range of 175–250 °C (65.0–68.9 g S/100 g sorbent). The sulfided materials were further analyzed with LA-XRD, WA-XRD, N 2 sorption studies, FESEM, FESEM-EDX, TEM, FETEM-EDX, TGA, and TPO. The M-Co-250 material reached 100% theoretical sulfur capacity at 150 °C. The presence of interconnected intraparticle voids and surface exposed particles were found to be the critical factors determining the ability of H 2 S to diffuse in the sorbent. The mesostruture of the M-Co-X material was preserved even after sulfidation. Other mesoporous metal oxides synthesized by the same method (Cr 2 O 3 (UCT-37), CuO (UCT-11), Mn 2 O 3 (UCT-1), and Fe 2 O 3 (UCT-5)) also showed sulfur capacities of 2–200 times more than the corresponding nonporous materials.