AI 中文总结
研究三水铝石和重水冰中电子激发解吸D原子，用2 + 1 REMPI - TOF质谱在不同温度下研究。发现冷却会降低产率，确定空穴传输到末端羟基位点是限速步骤，为理解相关原子氢释放提供机制框架。
AI 中文摘要
利用2 + 1共振增强多光子电离（REMPI）飞行时间质谱，在15K和300K温度下的高真空室中，研究了从三水铝石（\ce{Al(OD)3}）纳米片和非晶态\ce{D2O}冰中电子激发解吸（ESD）中性D原子的情况。540、250和150eV的电子辐照在约300K时产生相似的平动能分布，有占主导的中间温度成分（T ~ 1500 - 2100K）。冷却到15K使D原子产率降低约50%并消除最低温度成分。相同条件下，\ce{D2O}非晶态固体水冰膜产生的D原子信号比裸三水铝石大20倍，平动能分布更热。结果表明空穴传输到末端羟基位点是非热D原子产生的限速步骤，为理解汉福德场地放射性废物储存中氢氧化铝相的原子氢释放提供了机制框架。
英文摘要
The electron-stimulated desorption (ESD) of neutral D atoms from gibbsite (\ce{Al(OD)3}) nanoplatelets and amorphous \ce{D2O} ice has been investigated using $2+1$ resonance-enhanced multiphoton ionization (REMPI) time-of-flight mass spectroscopy in a high vacuum chamber at temperatures 15 and 300\,K. Electron irradiation at 540, 250, and 150\,eV produces similar translational energy distributions at $\sim$300\,K, with a dominant intermediate-temperature component ($T \sim 1500$--$2100$\,K). Cooling to 15\,K suppresses the D atom yield by approximately 50\% and removes the lowest-temperature (slowest) component. This decrease in yield is consistent with diminished hole mobility and restricted diffusion at cryogenic temperatures. Under identical conditions, \ce{D2O} amorphous solid water ice films produce approximately 20 times greater D atom signal than bare gibbsite, with significantly hotter translational distributions, reflecting the higher deuterium surface density and distinct bonding environments of bulk ice relative to the terminal hydroxyl groups on gibbsite. These results identify hole transport to terminal hydroxyl sites as the rate-limiting step for nonthermal D atom production and provide a mechanistic framework for understanding atomic hydrogen release from aluminum hydroxide phases relevant to radioactive waste storage at the Hanford Site.
Comments10 pages, 6 figures, to be published in Journal of Chemical Physics (AIP)
