Shape-selective methylation of 4-methylbiphenyl was studied using zeolites HY. HM and HZSM-5 under the down-flow conditions. HY and HM display no shape selectivity, but HZSM-5 shows moderate selectivity to the target product, 4,4'-dimethylbiphenyl (4,4'-DMBP). Increasing the crystal size and modifing the surface of HZSM-5 zeolite can improve the selectivity to 4,4'-DMBP. The modification of external and internal surface with inorganic P compound was found to be very effective. The selectivity to 4,4'-DMBP can be increased to as high as 65% over the HZSM-5 modified with a small amount of ammonium hydrogen phosphate.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry