Abstract: The present invention relates to a process for removing hetero-atoms from a hydrocarbonaceous feedstock using novel catalysts comprised of highly dispersed molybdenum sulfide promoted with a noble metal such that the noble metal is in an oxidation state greater than 0 and coordinated to S. The noble metal is selected from Pt, Pd, Rh, and Ir. It is preferred that the catalysts of be prepared from a precursor composition selected from platinum ethoxyethyl xanthate or platinum dithiocarbamate. Additionally, the catalyst may include a promotor sulfide such as nickel sulfide, cobalt sulfide or iron sulfide, etc. or mixtures thereof.

Abstract: A process for removing heteroatoms from a hydrocarbonaceous feedstock using a catalyst composition comprised of: about 0.005 to 5.0 wt. % noble metal, about 0.5 to 5 wt. % of at least one Group VIII metal, and about 3 to 18 wt. % of a Group VI metal, and a refractory support, wherein the noble metal is incorporated into the refractory support by use of a precursor represented by ML.sub.2 when the noble metal is Pt or Pd, and ML.sub.3, when the noble metal is Rh or Ir, where M is the noble metal and L is a ligand selected from the dithiocarbamates, dithiophosphates, dithiophosphinates, xanthates, thioxanthates, and further wherein L has organo groups having a sufficient number of carbon atoms to render the noble metal complex soluble in oil.

Abstract: This invention relates to the preparation of substituted noble metal xanthates having the formula (R.sub.1 OR.sub.2 OSC.sub.2).sub.n M, where R.sub.1 is an alkyl group, an alkoxy or polyalkoxy substituted alkyl group, an aryl group, or a substituted aryl group; R.sub.2 is an alkylene group; M is a noble metal selected from Pt, Rh, and Ir; n is 2 when M is Pt; and n is 3 when M is Rh or Ir.