Effect of proximity of strongly acidic centerson the hydroisomerization of n-hexane over zeolite catalysts was examined. High density of non-interacting but close and strongly acidic hydroxyls significantly lowersthe activation barrier. The unique high density of strongly acidic protonic sites is available in the Al-rich Pt/H-*BEA zeolite(Si/Al 4.2). Isomerizationactivity of the Al-rich Pt/H-*BEA zeolite highly exceeds that of state-of-the-art Si-rich zeolites.