Spillover of physisorbed hydrogen from sputter-deposited arrays of platinum nanoparticles to multi-walled carbon nanotubes

Ambient temperature and moderate pressure (300 K, 1.67 MPa) hydrogen storage and spillover in ultra-fine platinum nanoparticle dispersed on carbon nanotubes are studied volumetrically. Comparison of the experimentally observed spilt-over hydrogen contributions with the physisorbed hydrogen storage contributions of PtH2 and PtH4 reveals that up to 15 closed shells of platinum atoms physisorb and spill hydrogen over to CNTs.