The effect of propylene pressure on shape-selective isopropylation of biphenyl over H-mordenite
- National Institute of Materials and Chemical Research, Ibaraki (Japan); and others
The effect of propylene pressure on the isopropylation of biphenyl was investigated over a highly dealuminated H-mordenite HM(220) (SiO{sub 2}/Al{sub 2}O{sub 3}=220). The selectivity of 4,4{prime}-diisopropylbiphenyl (4,4{prime}-DIPB) was achieved up to 90% under such a high pressure as 8 kg/cm{sup 2}, whereas the selectivity of 4,4{prime}-DIPB decreased with the increase of that of 3,4{prime}-DIPB under such a low pressure as 0.8 kg/cm{sup 2}. However, no effect reached maximum at 50-60% conversion, whereas that of 3-IPBP increased monotonously. The change of the selectivity of DIPB isomers is ascribed to the isomerization of 4,4{prime}-DIPB, but not to the change of shape-selectivity because the total yield of DIPB isomers was not affected by the pressure. The extensive isomerization and the isopropylation of 4,4{prime}-DIPB did not occur significantly under pressure higher than 3 that the high selectivity under high pressures is due to the prevention of the adsorption of biphenyl on acid sites because of the preferential adsorption of propylene on acid sites, and that the isomerization of 4,4{prime}-DIPB under low pressures occurred on external acid sites that no propylene was adsorbed.
- OSTI ID:
- 214769
- Report Number(s):
- CONF-950801--
- Country of Publication:
- United States
- Language:
- English
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