Innovative approaches to hydrogen storage in vinyl aromatic polymers

Hydrogen energy presents a promising alternative to conventional fuels due to its clean and renewable nature. However, effective storage solutions are crucial for its practical application and widespread adoption. This research explores the effectiveness of vinyl aromatic polymers as solid-state hydrogen storage materials by optimizing their hydrogenation and dehydrogenation processes. We investigated five polymers, including poly (1-vinylanthracene), poly (N-vinylcarbazole), poly (9-vinylphenanthrene), poly (2-vinylnaphthalene), and polystyrene, using a three-phase heterogeneous catalytic system. Hydrogenation was conducted with Ru/Al2O3, while dehydrogenation was carried out with Pd/Al2O3. We analyzed structural changes by Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. The results revealed significant variations in hydrogen storage performance among these polymers. Poly (9-vinylphenanthrene) exhibited a high gravimetric hydrogen uptake of 5.78 %, with hydrogenation and dehydrogenation yields of 90 % and 98 %, respectively. Poly (2-vinylnaphthalene) demonstrated an 80 % hydrogenation yield, a 98 % dehydrogenation yield, and a gravimetric hydrogen uptake of 4.90 %. In comparison, polystyrene, poly (1-vinylanthracene), and poly (N-vinylcarbazole) had lower hydrogen uptake values of hydrogen (4.59 %, 3.73 %, and 2.03 %, respectively). These findings highlight the potential of vinylaromatic polymers for efficient hydrogen storage and their suitability both for transportation and practical applications of hydrogen.