Hydrogen production via steam reforming of n-dodecane over NiPt alloy catalysts

•Pt addition leads to smaller Ni particle and more moderate metal-support NiO species.•Pt addition suppresses coking effectively via forming amorphous carbon.•Performance of NiPt bimetallic catalyst is enhanced at least three fold compared with that of Ni/Al2O3.•H2 molar yield over NiPt bimetallic catalyst is as high as fivefold compared with that of Ni/Al2O3.•No obvious deactivation is observed over NiPt1.0/Al2O3 catalyst in 25 h steam reforming of n-dodecane process.