The nature of interfacial catalysis over Pt/NiAl2O4: Effects of metal identity and CO tolerance in hydrogen production from methanol reforming reaction

Abstract

In this study, we investigate the effect of interfacial structure on the methanol steam reforming (MSR) reaction by systematically varying the transition metals (Pt, Ru, Rh, Pd, and Ir) over a NiAl₂O₄ support. At similar methanol conversions at ∼ 5 %, H₂ formation exhibits superior reaction performance at ∼ 0.14 mol_H2·mol_metal^-1·s⁻¹ over Pt/NiAl₂O₄ than any other counter parts, which was attributed to the enhanced ability in tolerance of CO from catalytic surface and the greater ability in CH₃O– activation with the activation energies of MSR, methanol dehydrogenation (MD), and water-gas shift (WGS) reaction at 70 kJ/mol, 79 kJ/mol, and 97 kJ/mol, respectively, which is obviously smaller than the other transition metal catalysts. More importantly, the higher reduction degree of Pt and more stabilized transition state along methanol activation might be additional reasons for this superior reaction performance on H₂ formation.