The influence of Brønsted acid strength on catalytic reactivity of carbenium ion was systematically studied by density functional theory (DFT) calculations. Four typical reactions of C4 carbenium ion as model compound

including hydrogen transfer

isomerization

β scission

and dehydrogenation

were simulated in five solid acid models with various acid strengths from weak-

strong-

even close to super-acid. The calculation results revealed that the reaction energy barrier decreased exponentially for hydrogen transfer reaction but decreased linearly for other three reactions with the increase of Brønsted acid strength. In weak-acid range

the sensitivities of reactions to acid strength from high to low was:hydrogen transfer > isomerization > β scission > dehydrogenation. Hydrogen transfer reaction had the lowest sensitivity in the strong-acid range. Calculation on ionic character of the organic fragments in transition states showed that reaction sensitivity to acid strength could be related to Mulliken charges of the transition state. The transition state with more Mulliken charge lead to stronger interaction with acid such that the activation energy barrier could be effectively reduced by increasing acid strength. The calculation was consistent with experimental conclusion and explained acid strength on production yield at the atomic level

which is of great significance to the development of new catalytic materials and modification of current catalysts.