Water Formation through a Quantum Tunneling Surface Reaction, OH + H2, at 10 K

TL;DR

This study provides the first experimental evidence that solid water forms via OH + H2 surface reaction at 10 K, highlighting quantum tunneling as the key mechanism and revealing a significant isotope effect.

Contribution

First experimental demonstration of water formation from H2 at 10 K via quantum tunneling, showing a substantial isotope effect compared to D2 reactions.

Findings

Solid H2O forms at 10 K through OH + H2 reaction.

H2O formation is more efficient than HDO formation by about an order of magnitude.

Quantum tunneling is identified as the reaction mechanism.

Abstract

The present study experimentally demonstrated that solid H2O is formed through the surface reaction OH + H2 at 10 K. This is the first experimental evidence of solid H2O formation using hydrogen in its molecular form at temperatures as low as 10 K. We further found that H2O formation through the reaction OH + H2 is about one order of magnitude more effective than HDO formation through the reaction OH + D2. This significant isotope effect results from differences in the effective mass of each reaction, indicating that the reactions proceed through quantum tunneling.