Facilitated hydrogen release kinetics from amine borane functionalization on gate-opening metal-organic framework

Insight into the Catalytic Effects of Open Metal Sites in Metal–Organic Frameworks on Hydride Dehydrogenation via Nanoconfinement

“…The results indicate that Cu-BDC bulk crystal constructed by Cu–O covalent bonds between layers has microporous structure with the BET specific surface area (SSA) about 550 m 2 /g, which corresponds well with the literature data ranging from ∼300 to ∼600 m 2 /g. ,, One pore size distribution from the H–K model can be seen at 13 Å, agreeing with reports varying from 5 to 12 Å as well. ,, It can be concluded that we are capable of reproducing Cu-BDC bulk crystals with reasonable textural properties. After AB addition to Cu-BDC, the reduced nitrogen adsorption implies possible pore blockage by confined AB, ,, which agrees with AB diffraction invisibility discussed in the PXRD section above.…”

“…42,51,55 It can be concluded that we are capable of reproducing Cu-BDC bulk crystals with reasonable textural properties. After AB addition to Cu-BDC, the reduced nitrogen adsorption implies possible pore blockage by confined AB, 23,33,59 which agrees with AB diffraction invisibility discussed in the PXRD section above.…”

“…The rate constant k is approached with the assumption of the firstorder reaction in kinetics curve fitting, considering the hydrogen generation yield (the ratio of equivalent H 2 generation to the maximum capacity) as a function of time, n H 2 (t)/n H 2 max (t → ∞) = 1 − e −kt . 23 Based on the calculations, the activation energies for hydrogen production from AB confined in Cu-BDC MOFs with/without desolvation are 101.9 and 173.5 kJ/mol, respectively. Compared to the literature data of pure AB E a from 150 to 200 kJ/mol, 15,21 clear improvement from MOF with open metal sites can be seen, while Cu-BDC with residual DMF has limited influence on AB dehydrogenation kinetics.…”

“…The E a is calculated from the slope of ln­( k ) vs 1/ T in the equation of ln­( k ) = ln­( A ) – E a /( RT ) (Figure C). The rate constant k is approached with the assumption of the first-order reaction in kinetics curve fitting, considering the hydrogen generation yield (the ratio of equivalent H 2 generation to the maximum capacity) as a function of time, n H 2 ( t )/ n H 2 max ( t → ∞) = 1 – e – kt . Based on the calculations, the activation energies for hydrogen production from AB confined in Cu-BDC MOFs with/without desolvation are 101.9 and 173.5 kJ/mol, respectively.…”

“…To deal with the above-mentioned obstacles in AB dehydrogenation, several modification techniques have been applied, such as catalysts, , AB derivation, , and nanoconfinement . In particular, AB nanoconfined in porous materials via physical mixing or deliquescence infiltration methods shows effectiveness concurrently on reduced dehydrogenation temperature, suppressed byproducts, and facilitated kinetics.…”