Unravelling acidity–selectivity relationship in the bifunctional process of Fischer-Tropsch synthesis and catalytic cracking

•Model catalysts were prepared by physically mixing FTS catalysts and H-ZSM-5.•The Brønsted acid sites (BAS) evolved well after addition of the H-ZSM-5.•The physically mixed H-ZSM-5 did not deteriorate the activity of FTS catalysts.•The C5–C20 selectivity significantly improved with increased H-ZSM-5 fractions.•A linear correlation was observed between cracking rate and BAS concentration.