H₂ + H₂O → H₄O: Synthesizing Hyperhydrogenated Water in Small-Sized Fullerenes?

Nanoscale confinement provides an ideal platform to rouse some exceptional reactions which cannot happen in the open space. Intuitively, H₂ and H₂O cannot react. Herein, through utilizing small-sized fullerenes (C₂₄, C₂₆, C₂₈, and C₃₀) as nanoreactors, we demonstrate that a hyperhydrogenated water species, H₄O, can be easily formed using H₂ and H₂O under ambient conditions by ab initio molecular dynamics simulations. The H₄O molecule rotates freely in the cavity of the cages and maintains its structure during the simulations. Further theoretical analysis indicates that H₄O in the fullerene possesses high stability thermodynamically and chemically, which can be rationalized by the electron transfer between H₄O and the fullerene. This work highlights the possibility of utilizing fullerene as a nanoreactor to provide confinement constraints for unexpected chemistry.