H-2 and CO2 uptake for hydrogen titanate (H2Ti3O7) nanotubes and nanorods at ambient temperature and pressure

Abstract

H-2 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 Si-29 CP-MAS NMR spectrum. H-2 and CO2 uptake on several hydrogen titanate samples was obtained by a TGA Q50 analyzer in flowing N-2 gas of 40 mL/min and CO2 gas of 60 mL/min at 25 degrees C and 1 atm. Pristine HTNT sample showed the highest H-2 uptake (i.e. similar to 12.5 mmol/g) on a TGA microbalance at 25 degrees C whereas amine-modified HTNT sample exhibited the highest CO2 uptake (i.e. similar to 1.2 mmol/g) among all samples studied. CO2/N-2 and H-2/N-2 selectivity for pristine and amine modified HTNT samples was investigated by comparing the weight of the sample in flowing pure N2 gas of 100 mL/min with above-mentioned mixed flows at 25 degrees C. Reversibility for CO2 and H-2 uptake showed good performance for 9 cycles. (C) 2016 Elsevier B.V. All rights reserved.