Nuclear spin conversion of molecular hydrogen on amorphous solid water in the presence of O2 traces

被引：36

作者：

Chehrouri, M. ^{[2
,3
,4
]}

Fillion, J-H. ^{[1
,5
]}

Chaabouni, H. ^{[2
,3
]}

Mokrane, H. ^{[2
,3
]}

Congiu, E. ^{[2
,3
]}

Dulieu, F. ^{[2
,3
]}

Matar, E. ^{[2
,3
]}

Michaut, X. ^{[1
,5
]}

Lemaire, J. L. ^{[2
,3
]}

机构：

[1] Univ Paris 06, UMR 7092, LPMAA, F-75005 Paris, France

[2] Observ Paris, LAMAp LERMA, UMR8112, CNRS, F-95000 Cergy Pontoise, France

[3] Univ Cergy Pontoise, F-95000 Cergy Pontoise, France

[4] Univ Saida, LEPC, E NSAR, Saida 20002, Algeria

[5] LPMAA, CNRS, UMR 7092, F-75005 Paris, France

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2011年 / 13卷 / 06期

关键词：

H2; CONVERSION; H-2; TEMPERATURE; DIFFUSION; FUNDAMENTALS; CONVERTER; COMPACT;

D O I：

10.1039/c0cp01322f

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Nuclear spin conversion (NSC) of ortho-to para-H-2 and para- to ortho-D-2 has been investigated on an amorphous solid water (ASW) surface at 10 K, in the presence of co-adsorbed O-2. The dynamics of the nuclear spin conversion could be revealed by combination of resonance enhanced multiphoton ionization spectroscopy (REMPI) with temperature programmed desorption (TPD) experiments. The conversion rates are consistent with a diffusion of molecular hydrogen inducing a nuclear spin conversion enhanced in the vicinity of molecular oxygen. The conversion times were found to increase with decreasing O-2 and H-2 coverage. Finally, on oxygen free ASW surface, the extremely long conversion characteristic times measured showed that such surface is not an efficient catalyst for NSC, in contradiction with hypothesis commonly made for interstellar medium.

引用

页码：2172 / 2178

页数：7

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