Strategic structure modulation of novel quinoxaline-derived liquid organic hydrogen carriers for enhanced dehydrogenation kinetics.

This study introduces novel Liquid Organic Hydrogen Carriers (LOHCs) derived from quinoxaline. It shows that strategically incorporating N atoms and methyl groups markedly improves the hydrogen release kinetics. This structural modulation optimizes the adsorption properties and enables low-temp C-H bond activation, providing valuable insights for developing efficient LOHCs.

Study of catalytic hydrogenation and dehydrogenation of 2,3-dimethylindole for hydrogen storage application.

2,3-Dimethylindole (2,3-DMID), a candidate with a hydrogen storage capacity of 5.23 wt%, was studied as a new liquid organic hydrogen carrier (LOHC) in detail in this report. Hydrogenation of 2,3-DMID was conducted over 5 wt% Ru/Al2O3 by investigating the influences of temperature and hydrogen pressure. 100% of fully hydrogenated product, 8H-2,3-DMID can be achieved at 190 °C and 7 MPa in 4 h. Dehydrogenation of 8H-2,3-DMID was performed over 5 wt% Pd/Al2O3 at 180-210 °C and 101 kPa. It is found that dehydrogenation of 8H-2,3-DMID followed first order kinetics with an apparent activation energy of 39.6 kJ mol-1. The structures of intermediates produced in the 8H-2,3-DMID dehydrogenation process were analyzed by DFT calculations.