In　the　present　work,　the　selective　hydrodeoxygenation　(HDO)　performance　of　stearic　acid　over　in　situ　MoS2　catalysts　produced　from　various　Mo　precursors　was　evaluated.　Notably,　the　in　situ　MoS2　catalyst　generated　from　[N8881]2MoO4—a　Mo-based　ionic　liquid　(IL)　with　oil-soluble　property—achieves　up　to　99.9%　of　stearic　acid　conversion　with　the　HDO　product　octadecane　yield　of　97.5%　at　300°C,　8　MPa,　and　6　h.　The　activity　of　[N8881]2MoO4　for　catalyzing　the　selective　HDO　reaction　is　much　better　than　commercial　precursors　like　Mo(CO)6　and　(NH4)6Mo7O24.　The　in　situ　MoS2　catalysts　were　thoroughly　characterized　and　analyzed　to　elucidate　the　experimental　results.　Moreover,　the　reaction　pathway　of　stearic　acid　was　proposed　according　to　the　product　distribution,　and　the　relative　kinetic　parameters　were　also　calculated　and　discussed.　The　results　indicate　that　applying　Mo-based　IL　as　the　precursor　to　generate　in　situ　MoS2　catalyst　for　the　selective　HDO　of　biolipids　is　highly　interesting　and　desired.　©　2025　American　Institute　of　Chemical　Engineers.