2-(N-Methylbenzyl)pyridine: A Potential Liquid Organic Hydrogen Carrier with Fast H₂ Release and Stable Activity in Consecutive Cycles

Abstract

The liquid organic hydrogen carrier (LOHC) 2-(N-methylbenzyl)pyridine (MBP) shows good potential for H-2 storage based on reversible hydrogenation and dehydrogenation, with an H-2 storage density of 6.15wt%. This material and the corresponding perhydro product (H-12-MBP) are liquids at room temperature. Remarkably, H-2 release is much faster from H-12-MBP over Pd/C than from the benchmark perhydro benzyltoluene over Pt/C at lower temperatures than 270 degrees C, owing to the addition of N atom into the benzene ring. Since this positive effect is unfavorable to the hydrogenation reaction, more Ru/Al2O3 catalyst or prolonged reaction time must be applied for complete H-2 storage. Experiments with repeated hydrogenation-dehydrogenation cycles reveal that reversible H-2 storage and release are possible without degradation of the MBP/H-12-MBP pair. The prepared MBP satisfies the requirements for chemical stability, handling properties, and cytotoxicity testing.