Hydrogenation of dibenzyltoluene and the catalytic performance of Pt/ <scp> Al <sub>2</sub> O <sub>3</sub> </scp> with various Pt loadings for hydrogen production from perhydro‐dibenzyltoluene
Ahsan Ali, Ajith Krishnan Rohini, Young Su Noh, Dong Ju Moon, Hee Joon Lee
Abstract
The characteristics of the hydrogenation of dibenzyltoluene and dehydrogenation of perhydro-dibenzyltoluene (H18-DBT) are investigated. The hydrogenation experiments are conducted using Raney-Ni. It is found that 170°C and 7 MPa is the optimal reaction condition at which the hydrogen capacity of 6.2 wt% is achieved in 30 hours. The optimal temperature for the dehydrogenation of H18-DBT is found to be 290°C. Moreover, the dehydrogenation of H18-DBT is carried out over Pt/Al2O3 catalysts with different Pt metal loadings (1% ~ 5%). The results elucidate that 5% Pt/Al2O3 is the most active catalyst yielding 90.2% of the stored hydrogen in 7 hours. The catalytic activity of the catalysts is in the order 5% > 4% > 3% > 2% > 1% Pt/Al2O3. The increment in catalyst dosage increases the reaction rate and hydrogen yield%. Lastly, the cyclic experiments are conducted and DBT is found to be quite stable in all three cycles. HIGHLIGHTS The complete hydrogenation (6.2 wt%) of dibenzyltoluene is achieved at 170°C and 5 ~ 7 MPa. The dehydrogenation of perhydro-dibenzyltoluene is conducted over 1 ~ 5% Pt/Al2O3. The 90.2% of stored hydrogen is produced over the optimal catalyst, 5% Pt/Al2O3. The hydrogen production in all the three cycles is almost similar which makes dibenzyltoluene a stable liquid organic hydrogen carrier.