This invention relates to a process for making a germanium-zeolite. The zeolite
is preferably a MFI-type structure, most preferably a ZSM-5 MFI zeolite. The germanium-zeolite
is synthesized from an aqueous gel containing a silica source, a germanium source,
an aluminum source and a structure directing agent in the presence of an acid to
control the pH of the gel in the range of 6.5 to 13.5, preferably 7.5 to 11, to
maximize the amount of germanium incorporated into the zeolite framework. Optionally,
a sodium compound may be introduced into the reaction mixture gel either before
or after the addition of the acid, preferably before.