Nanoscale visualization of plasmon-enhanced hydrogen activation on a Pt(111) surface

Abstract Efficient H 2 activation under mild conditions is crucial for achieving energy-efficient catalytic hydrogenation, but this remains a major challenge. Here we demonstrate nanoscale visualization of plasmon-enhanced H 2 activation on Pt(111) at room temperature under visible light by employing a combination of spectroscopic and modelling methods. In situ tip-enhanced Raman spectroscopy tracked H 2 activation through H-assisted desorption of an oligomeric phenylene–ethynylene thiolate reporter, while hyperspectral imaging revealed ~20% enhancement in the 180–300 nm region around the near field. Spectroscopic evidence and finite element method simulations excluded the plasmonic heating effect, whereas quantum calculations showed that hot electrons generated in the tip-enhanced Raman spectroscopy near field can efficiently drive H 2 dissociation via an indirect transfer mechanism. Notably, we found that activated H atoms propagate hundreds of nanometres beyond the near field through a collective crowd effect. These findings provide mechanistic insights into plasmon-enhanced H 2 activation on Pt surfaces and suggest future opportunities for energy-efficient catalytic hydrogenation.