A catalyst precursor composition and methods for making such catalyst precursor are disclosed. The catalyst precursor comprises at least a metal compound selected from Group VIII, Group IIB, Group IIA, Group IVA and combinations thereof, at least one Group VIB metal, at least one organic, oxygen-containing ligand, and a cellulose-containing material. Catalysts prepared from the sulfidation of such catalyst precursors are used in the hydroprocessing of hydrocarbon feeds. In one embodiment, the sulfidation is carried out by contacting the catalyst precursor with hydrogen and a sulfur containing compound in a “slow” process with the sulfidation taking place over a few days up to two weeks, e.g., for at least over 96 hours. In another embodiment, the sulfidation is in a “quick” process with the sulfidation taking place in less than 72 hours. The catalyst prepared from the slow sulfidation process gives a 700° F.+ conversion rate of at least 25% higher than the 700° F.+ conversion rate of a catalyst prepared from a quick sulfidation process.