当前位置:科学网首页 > 小柯机器人 >详情
介孔二氧化硅上超密氢单层的形成
作者:小柯机器人 发布时间:2022/8/31 14:48:46

德国马克思普朗克智能系统研究所Hirscher, Michael团队报道了介孔二氧化硅上形成超密氢单层。相关研究成果于2022年8月29日发表于国际顶尖学术期刊《自然—化学》。

在接近沸点的温度下,氢和氦在各种吸附剂上的吸附在某些情况下显示出异常高的单层容量。然而,低温下这些吸附质相的微观性质仍然难以表征。

该文中,使用高分辨率低温吸附研究以及非弹性中子散射振动光谱表征发现,在沸点(~20K)附近,吸附在有序介孔二氧化硅上的H2形成了一个密度是固体H2的两倍以上的二维单层,而不是双层。

基于彻底的第一性原理计算理论研究解释了这种超密相的形成。氢表面层的强压缩是由于表面-氢吸引力超过分子间氢的斥力。与77K下的吸附相比,在吸附剂上使用这种超密氢单分子层可能是在沸点附近储存氢的可行选择。

附:英文原文

Title: Formation of a super-dense hydrogen monolayer on mesoporous silica

Author: Balderas-Xicohtncatl, Rafael, Lin, Hung-Hsuan, Lurz, Christian, Daemen, Luke, Cheng, Yongqiang, Cychosz Struckhoff, Katie, Guillet-Nicolas, Remy, Schtz, Gisela, Heine, Thomas, Ramirez-Cuesta, Anibal J., Thommes, Matthias, Hirscher, Michael

Issue&Volume: 2022-08-29

Abstract: Adsorption on various adsorbents of hydrogen and helium at temperatures close to their boiling points shows, in some cases, unusually high monolayer capacities. The microscopic nature of these adsorbate phases at low temperatures has, however, remained challenging to characterize. Here, using high-resolution cryo-adsorption studies together with characterization by inelastic neutron scattering vibration spectroscopy, we show that, near its boiling point (~20K), H2 adsorbed on a well-ordered mesoporous silica forms a two-dimensional monolayer with a density more than twice that of bulk-solid H2, rather than a bilayer. Theoretical studies, based on thorough first-principles calculations, rationalize the formation of such a super-dense phase. The strong compression of the hydrogen surface layer is due to the excess of surface–hydrogen attraction over intermolecular hydrogen repulsion. Use of this super-dense hydrogen monolayer on an adsorbent might be a feasible option for the storage of hydrogen near its boiling point, compared with adsorption at 77K.

DOI: 10.1038/s41557-022-01019-7

Source: https://www.nature.com/articles/s41557-022-01019-7

期刊信息

Nature Chemistry:《自然—化学》,创刊于2009年。隶属于施普林格·自然出版集团,最新IF:21.687
官方网址:https://www.nature.com/nchem/
投稿链接:https://mts-nchem.nature.com/cgi-bin/main.plex