Influence of defect engineering on the hydrogen and methane adsorption capacity in HKUST-1 – like structure MOF

Abstract

Samples with HKUST-1-like structure were modified by the substitution of trimesic acid (BTC) by isophthalic acid (iBDC). HKUST-1-like structure was monitored by XRD, finding no changes up to a BTC molar fraction (XBTC) equal to 0.67. The substitution of BTC by iBDC produced an increase of defects observed by SEM and led to a greater specific surface area. The increase in N2 molecules adsorption was correlated with a 10% increase in H2 uptake at 8 bar and 77 K. Interestingly, the ligand substitution showed no effects on methane uptake up to 40 bar and 298 K. The defect engineering showed to be a useful tool to increase the uptake of polar molecules with surface.