Synthesis of 4-methyl-2-pentanone, better known as methyl isobutyl ketone (MIBK), from propanone (Ac) was studied in a fixed-bed and a Bow reactor at 160 degrees C, 1 atm and an H-2/Ac molar ratio equal to 0.33, using Pt-H[Al]ZSM5 bifunctional catalysts with variable platinum percentage and Si/Al ratio. The results how that initial total activity to all measured products at t = 0, per acidic site (A(o)/nA), residual activity (A(r) = A(265)/A(0). ratio of activity after 265 min of stream and the initial total activity to all measured products at t = 0) and initial formation rate of each product per acidic site (R-o/nA) largely depend on the relationship between the number of hydro-dehydrogenating, metallic sites and the number of theoretical acidic sites(nPt/nA) present in the catalysts used.