Supported　Ni-Cu　alloy　nanoparticles　prepared　from　Ni-Cu-Mg-Al　hydrotalcite-like　compounds　(HTlcs)　with　Cu/Ni　=　0.25　have　been　shown　to　be　an　active　catalyst　for　the　steam　reforming　of　tar　derived　from　the　biomass　pyrolysis.　In　the　present　work,　Ni-Cu　alloy　catalysts　with　wider　compositions　of　Cu/Ni　were　characterized　and　their　performances　were　evaluated　in　the　steam　reforming　of　1-methylnaphthalene　(1-MN),　which　has　lower　reactivity　than　the　biomass　tar,　in　order　to　make　the　effect　of　Cu/Ni　much　clearer.　The　characterizations　with　XRD,　STEM-EDX,　H2　chemisorption,　and　FIIR　of　CO　adsorption　suggest　that　the　obtained　Ni-Cu　alloy　nanoparticles　had　uniform　composition　in　the　range　of　Cu/Ni　=　0.1-1;　the　particle　size　was　decreased　with　the　increase　of　Cu/Ni　ratio　(ca.　5-7　nm),　and　Cu　tended　to　be　enriched　on　the　particle　surface.　The　HTlcs-derived　Ni-Cu　alloy　catalysts　showed　a　volcano-type　dependence　of　activity　on　the　alloy　composition;　the　highest　reforming　activity　and　lower　yields　of　byproducts　including　benzene,　naphthalene,　and　coke　were　obtained　at　Cu/Ni　=　0.25.　The　kinetic　study　indicates　that　1-MN　was　strongly　adsorbed　on　both　the　Ni　and　Ni-Cu　catalysts;　in　contrast,　the　adsorption　of　steam　was　promoted　by　the　alloying　of　Ni　with　Cu　even　in　the　presence　of　strongly　adsorbed　1-MN.　The　property　of　stronger　adsorption　of　steam　can　be　connected　to　higher　reforming　activity　and　lower　coke　deposition　through　the　dissociative　adsorption　of　steam　to　supply　more　adsorbed　oxygen　species,　which　enhance　the　gasification　of　carbonaceous　species.　©　2016　Elsevier　B.V.