This is based on an old patent by Nedelko 'Nick' Delchev [1] where he proposes to mix an oxidizer and fuel in concentrations such that the mix is stable until exposed to a catalyst. The inventor envisioned applications in the automobile and power generation domains, but it would be more useful in anaerobic conditions like submarine and spacecraft propulsion.

This concept use the Delchev mix as the base for liquid, solid and 'hybrid' rockets. It takes advantage of the simplicity of having only one propellant, which can be created from simple substances like water and sugar [2]. The graphite foam is an good example of an advanced material created by putting a well-known material (bread) through a well-known process (pyrolysis) [3].

[1] https://patentimages.storage.google...../US4698965.pdf
[2] https://www.cia.gov/library/abbotta....._fuel_cell.pdf
[3] https://www.acsh.org/news/2016/07/0.....nt-carbon-foam