Abstract: A porous solid such as a zeolite of clay can be degassed to make it suitable as an adsorbent, after which the entrances of the pores are narrowed to a desired size by treating the porous solid with two chemisorbable materials, one of which is diborane. The treatment may be repeated.The purpose of the first such treatment is to make the pore entrances so narrow, that unduly large molecules cannot enter and the smaller ones can, while a later treatment may serve to narrow the pores still further, so that the adsorbed molecules cannot escape.

Abstract: A clay material of the polygorskite group, pretreated or not, is degassed and contacted with a gas to be adsorbed and after adsorption the clay is heated while in contact with the gas so that the clay structure collapses, encapsulating the adsorbed gas. If desired the entrances of the pores may be narrowed to a desired size by adsorption of diborane before the adsorption of the gas.

Abstract: The present invention relates to compounds, elements or ions encapsulated in a zeolite in a stable manner by adsorption, chemisorption or ion exchange, by using a zeolite treated before together with, or after the introduction of the material to be enclosed with a modifying agent selected from the group consisting of silanes, boranes and germanes, which may be substituted by one or more halogen atoms and/or hydrocarbon groups, and after the introduction closing the pores by a further treatment with the modifying agent and/or by an oxidation treatment.