Actually, you can put just about any liquid chemical onto a solid structure, using porous solids as a type of scaffolding. Also, you can easily generate hydrogen peroxide from solids such as percarbonate. There are plenty of peroxides (not hydrogen) that are solid at room temperature (calcium peroxide is an example). And many compounds that are not peroxides but that can generate a good explosion (such as metalic sodium) are solids.

There is nothing inherently dangerous about the liquid state of matter. The liquid madness makes no sense from a scientific standpoint. It is about control, theatrics, and the need to maintain jobs created for make-believe threats.