A　series　of　supported　Ni-Mo-P　alloy　catalysts　was　studied　for　the　catalytic　hydrodeoxygenation　(HDO)　of　the　cyclic　five-membered　ester　gamma-valerolactone　(GVL-C5H8O2)　as　a　model　compound　for　pyrolysis　oil.　Alloy　formation　in　Ni-Mo-P　was　indicated　by　X-ray　diffraction　analysis　and　X-ray　absorption　near-edge　spectroscopy,　which　showed　systematic　shifts　with　composition.　The　number　of　active　sites　of　each　metal　species　was　estimated　by　factor　analysis　combining　CO-uptake　measurements　and　infrared　(IR)　spectra　of　adsorbed　CO.　It　was　found　that　the　catalytic　activity　followed　the　order:　Ni2P/MCM-41　＞　NiMo(3:1)P/MCM-41　＞　NiMo(1:1)P/MCM-41　congruent　to　(Ni2P　+　MoP)/MCM-41　＞　NiMo　(1:3)P/MCM-41　＞　MoP/MCM-41,　whereas　the　normalized　turnover　frequency　based　on　Ni　sites　were　similar　for　all　the　catalysts,　while　retaining　the　same　order.　It　is　concluded　that　adjacent　surface　Ni　atoms　are　the　main　active　sites　involved　in　the　rate-determining　step　(rds).　The　Mo-containing　catalysts　produced　more　1-pentanol　and　C5　hydrocarbons　than　Ni2P/MCM-41,　indicating　that　while　the　exposed　Ni　sites　governed　catalytic　activity,　Mo　sites　controlled　the　selectivity　to　C5　hydrocarbons.　Thus,　steps　following　the　rds　were　influenced　by　Mo　sites,　leading　to　preferences　for　different　reaction　pathway　during　the　HDO　of　gamma-valerolactone.　The　study　reveals　that　the　catalytic　behavior　of　NiMoP　catalysts　can　be　tuned　by　the　relative　proportion　of　Ni　and　Mo　sites.　(C)　2017　Elsevier　Inc.　All　rights　reserved.