Synthesis of novel aluminoborosilicate isomorphous to zeolite TUN and its acidic and catalytic properties

The novel TUN-type aluminoborosilicate zeolite (denoted as [Al, B]-TUN), which consists of a three-dimensional pore system with 10-ring, has been hydrothermally synthesized for the first time and implied in cracking reaction. mother gel composition including aluminum, boron, organic structure-directing agent sodium were intensively studied optimized. We found that incorporation B together Al T-sites into TUN framework led to control acidic properties number, strength distribution acid sites. n-hexane over different catalysts show B]-TUN zeolites have longer catalyst duration higher P/E ratio (propylene/ethylene selectivity) than [Al]-TUN. Moreover, comparison between TUN, MFI *BEA-type indicates preference propylene production. relationship carking behaviors discussed supported by constraint index (CI) value measurement.