Enhancing energy carrier gas storage: Novel MOF-decorated carbons with high affinity toward methane and hydrogen
Shohreh Mirzaei, Leila LotfiKatooli, Ali Ahmadpour, Mahdi Niknam Shahrak, Mohammad Reza Haghbin, Arash Arami‐Niya
Abstract
The low volumetric density of alternative energy sources, like methane and hydrogen, makes their efficient storage challenging. This issue hinders their widespread adoption as clean energy carriers and limits their potential in addressing the energy crisis and reducing CO2 emissions. To overcome this limitation, a novel hybrid adsorbent was synthesised by incorporating MIL-101(Cr) and pitch-based activated carbon (AC), and its potential for methane and hydrogen adsorption was evaluated through experimental and molecular simulation methods. The adsorption capacity of CH4 and H2 on the MOF-doped ACs was simulated using Grand Canonical Monte Carlo (GCMC). Through the ex-situ method, varying amounts of MIL-101(Cr) were integrated onto the surface of AC, resulting in a nanocomposite with enhanced gas uptake properties. The AC/MIL-101(Cr) nanocomposite with 50 wt.% MOF-doping exhibited superior methane loading performance (12.21 mmol/g) at room temperature and 35 bar, surpassing MIL-101(Cr) by approximately 20% (10.15 mmol/g). In terms of hydrogen adsorption, the AC/MIL-101 composites demonstrated advantageous gas uptake at low pressures (P ≤ 4.5 bar) due to a decrease in pore diameter (2.17 nm to 1.61 nm) and an increase in the number of micropores (60% to 78%). Conversely, at higher pressures, the dominant factor influencing H2 storage was the surface area.