Study of the enhanced hydrogen storage of NaAlH₄ by synergistic effects of nanoconfinement and nitrogen doping나노 구조화와 질소 도핑의 시너지 효과를 통한 수소화알루미늄 나트륨의 수소 저장 성능 개선 연구
Considering energy shortage and climate change, the demand for hydrogen as a new energy carrier has increased. The key challenge in the hydrogen energy system is safe and efficient hydrogen storage methods. Complex hydride such as $NaAlH_4$ is a fascinating candidate due to its high storage capacity. However, thermodynamic and kinetic barriers of complex hydride induce high-temperature conditions with low reversibility. To deal with such issues, the size of complex hydrides is reduced by confinement, or hetero-elements are doped to complex hydride, expecting enhanced storage properties through a shortened diffusion path, thermodynamically altered pathway, and catalytic effects. In our system, to optimize hydrogen sorption kinetics and thermodynamics, $NaAlH_4$ is nanoconfined into the nitrogen-doped porous carbon structure. The synergistic effects of nanosized $NaAlH_4$ and charge transfer from nitrogen provide the lowest activation energy for the dehydrogenation of $NaAlH_4$ composite. This strategy can be accommodated into other hydride-scaffold systems for overcoming practical barriers.