The invention relates to a method for treating an amino functional, polymeric catalyst precursor having a high water content, its inner porous structure and outer spherical shape being retained, forming a catalyst by treatment of the catalyst precursor at mild temperatures and low pressure and producing a catalyst having a water content of less than 2.5 % by weight. The method is preferably integrated into an industrial-scale process for producing dichlorosilane, monosilane, silane,or solar or semiconductor silicon from silanes.