Regenerable α-MnO2 nanotubes for elemental mercury removal from natural gas

摘要: Abstract The elemental mercury (Hg 0 ) vapor removal ability of α-MnO 2 nanotubes (NTs), nanorods (NRs) and nanowires (NWs) was evaluated in simulated natural gas mixtures. It shown that NTs exhibited superior efficiency (~100%) at the temperature range interest (25–100 °C). Hg breakthrough (corresponding to 99.5% efficiency) ambient conditions  = 870 μg∙m −3 , occurred after 48 h, reflecting a uptake >10 mg∙g −1 (1 wt%). Most importantly, developed nanosorbent repeatedly, sufficiently regenerated relatively low 250 °C series seven successive sorption-desorption tests, maintaining its capacity remove all incoming each cycle. Interestingly, kinetic studies showed least 85% total adhered could be recovered within first hour 3-h regeneration process. Moreover, presence CO H S did not affect activity. thermogravimetric analysis indicated significantly higher dehydration for due loss bound water inside tunnels, likely indicating abundant surface adsorbed oxygen species which are believed facilitate adsorption. This also confirmed by X-ray spectroscopy, possibly explaining enhanced activity NTs.