| 摘要 |
<p>This invention relates to the treatment of Group VIII, noble metal, catalysts, wherein said noble metal is present on a refractory support and where said noble metal exists is large agglomerated crystallites, e.g., greater than 50.ANG., which comprises contacting said catalyst with fluorine at a temperature and for a time sufficient to disperse said crystallites to crystallites having substantially smaller particle size. The noble metals which may be dispersed by this process include Pt, Pd, Ru, Ir and Rh. This invention is especially suitable for redispersing iridium-containing catalysts. In a preferred embodiment of the instant invention, an iridium containing reforming catalyst which has become at least partially deactivated because of the presence of carbonaceous deposits is regenerated by contacting, serially,(1) with an oxygen-containing gas at a temperature and for a time sufficient to substantially remove said carbonaceous deposits (2) with hydrogen at a temperature and for a time sufficient to convert said iridium substantially to its metallic form, and (3) with a fluorine-containing gas at a temperature of less than 300.degree.C for a time sufficient to yield a catalyst wherein the iridium is present in crystallites of relatively average particle size, e.g., less than 50.ANG..</p> |
