Metal-organic　frameworks　(MOFs)　have　shown　great　potential　for　application　in　various　fields,　including　CO2　capture　and　proton　conduction.　For　promoting　their　practical　applications,　both　optimization　of　a　given　property　and　enhancement　of　chemical　stability　are　crucial.　In　this　work,　three　base-stable　isostructural　MOFs,　[Ni-8(OH)(4)(H2O)(2)(BDP-X)(6)]　(Ni-BDP-X;　H2BDP=　1,4-bis(4-pyrazolyl)benzene,　X=　CHO,　CN,　COOH)　with　different　functional　groups,　are　designed,　synthesized,　and　used　in　CO2　capture　and　proton　conduction　experiments.　They　possess　face-centered　cubic　topological　structures　with　functional　nanoscale　cavities.　Importantly,　these　MOFs　are　fairly　stable　to　maintain　their　structures　in　boiling　water　and　4M　sodium　hydroxide　solution　at　room　temperature.　Functionalization　endows　them　with　tunable　properties.　In　gas　adsorption　studies,　these　MOFs　exhibit　selective　adsorption　of　CO2　over　CH4　and　N-2,　and　in　particular　the　introduction　of　COOH　groups　provides　the　highest　selectivity.　In　addition,　the　COOH-functionalized　Ni-BDP　exhibits　a　high　proton　conductivity　of　2.22　x　10(-3)　Scm(-1)　at　80　degrees　C　and　approximately　97%　relative　humidity.