Burning ice in the Arctic

Clathrates, from the Latin clathratus, meaning to be encaged, are compounds formed by the inclusion of atoms or molecules of one kind in cavities of the crystal lattice of another. For over 100 years the only mention of clathrates in chemistry undergraduate texts were those of the noble gases, and then only as a laboratory curiosity. Noble gas clathrates comprise individual noble gas atoms trapped within the cavities of the hydrogen-bonded ice structure. The presence of the noble gas atom within each cavity stabilises the ice structure so that the melting point of the clathrate is above 0°C. More recently, there has been mention of carbon dioxide clathrates, which could be formed on the ocean floor if deep-sea disposal of industrial carbon dioxide came about.¹ Here, however, we focus on methane clathrates since they are a potential energy source for the future.