the range of about 40 weight percent silica to about 99 weight percent silica base materials suitable for preparing the catalysts used in the process of this invention are commercially available for example from condea chemie gmbh of hamburg germany and base materials from condea chemie designated as 34 siral 40 34 have been found to be particularly suitable to prepare catalysts employed in the present invention alternatively the silica alumina base materials are prepared using known coprecipitation cogelation and or comull procedures crystalline silica alumina materials such as zeolites may also be included as part of the support of the hydrogenation catalysts to increase catalyst acidity the amount of platinum palladium alloy placed on the support must be sufficient to act as an effective catalyst in the hydrogenation of the lubricating oil base stock generally the amount of alloy on the support used to catalyze a hydrogenation process within the scope of the present invention will be within the range of from about 0 01 weight percent to about 5 weight percent preferably the range is from about 0 1 weight percent to about 1 weight percent generally adding greater than about 1 weight percent of the alloy does not significantly improve on the activity of the catalyst and is therefore economically disadvantageous however amounts in excess of 1 weight percent are usually not harmful to the performance of the catalyst.