Synthesis of the composite material Y/ASA and its catalytic performance for the cracking of n-decane

► Y/ASA composite is firstly prepared by wrapping small-crystal Y zeolite in ASA gel. ► Y/ASA is a novel bi-modal porous composite with dispersed Y crystallites in ASA. ► Bonding action between Y zeolite and ASA generates new acid sites. ► More contact positions exist in Y/ASA composite with small-crystal size of Y zeolite. ► The crystal size of Y zeolite has relation with the acidic properties of Y/ASA composite.