H2 and CO2 uptake for hydrogen titanate (H2Ti3O7) nanotubes and nanorods at ambient temperature and pressure

Abstract

H2 and CO2 adsorption was investigated using pristine hydrogen titanate nanotube (HTNT) and nanorod (HTNR). HTNT and HTNR were modified with N-[3-(trimethoxysilyl)propyl]ethylene-diamine (TPEDA). Chemical linkage between an amine-containing organosilane and titanium on the surface of hydrogen titanate was confirmed with 29Si CP-MAS NMR spectrum. H2 and CO2 uptake on several hydrogen titanate samples was obtained by a TGA Q50 analyzer in flowing N2 gas of 40mL/min and CO2 gas of 60mL/min at 25°C and 1atm. Pristine HTNT sample showed the highest H2 uptake (i.e. ∼12.5mmol/g) on a TGA microbalance at 25°C whereas amine-modified HTNT sample exhibited the highest CO2 uptake (i.e. ∼1.2mmol/g) among all samples studied. CO2/N2 and H2/N2 selectivity for pristine and amine-modified HTNT samples was investigated by comparing the weight of the sample in flowing pure N2 gas of 100mL/min with above-mentioned mixed flows at 25°C. Reversibility for CO2 and H2 uptake showed good performance for 9 cycles.