Quantification of relevant Brønsted acid sites on Cl-doped alumina catalysts for the isomerization of olefins

•3,3′-dimethyl-1-butene isomerization activity is correlated to the concentration of moderate Brønsted acid sites.•2,6-di-tert-butylpyridine is are very sensitive IR probe for moderate Brønsted acid sites such as alumina supported catalysts.•A correlation between catalytic performance and acidity characterization is demonstrated for reforming catalysts.