Mg(Al)O　mixed　metal　oxide　(MMO)　supported　Cu　nanoparticles　catalysts　have　been　prepared　by　calcination　and　reduction　of　Cu-Mg-Al　layered　double　hydroxides　(LDHs).　By　adjusting　the　chemical　compositions　of　LDHs　precursors,　various　catalysts　with　10–40 wt%　Cu　content　and　molar　ratio　of　(Cu + Mg)/Al = 1–4　were　prepared.　The　catalysts　were　characterized　by　ICP,　N2　physical　adsorption,　XRD,　TEM,　H2-TPR,　and　N2O　chemisorption,　and　tested　for　the　water-gas　shift　(WGS)　reaction.　The　characterization　results　suggested　that　upon　calcination　Cu-Mg-Al　LDHs　were　converted　to　Mg(Cu,　Al)O　MMOs,　where　both　Cu2+　and　Al3+　were　incorporated　into　the　MgO　framework　to　form　a　solid　solution;　reduction　of　Mg(Cu,　Al)O　gave　highly　dispersed　and　uniform　Cu　metal　nanoparticles.　The　Cu　metal　dispersion　was　as　high　as　22–78%　and　the　particle　size　varied　from　1.5　to　5 nm　depending　on　the　chemical　compositions.　The　WGS　activity　of　the　Cu　catalysts　increased　with　the　increase　of　Cu0　surface　area.　Among　the　prepared　catalysts,　the　30%Cu/Mg2Al　catalyst　exhibited　the　highest　Cu　surface　area　and　the　highest　WGS　activity.　The　optimized　catalyst　also　showed　superior　activity,　thermal　stability,　and　steady-state　stability　than　a　commercial　Cu/ZnO/Al2O3　catalyst　under　the　present　reaction　conditions.　The　characterization　on　the　spent　catalysts　showed　that　the　LDHs-derived　Cu　nanoparticles　remained　highly　dispersed,　suggesting　that　the　Mg(Al)O　supported　Cu　nanoparticles　were　stable　and　possessed　good　resistance　against　sintering.　©　2016