The sorption and diffusion of a series of alcohols were measured on various microporous ammonium heteropoly oxometalates and on ZSM-5 zeolite (table 66). The sorption capacities, heats of sorption and diffusivities were compared and contrasted, and the factors responsible for the differences were considered. Whereas in ZSM-5 the pore size restriction predominated it was apparent that, in the larger pore heteropoly oxometalates, the electric field potential played an important role.

Sorption and Diffusion of Alcohols in Heteropoly Oxometalates and ZSM-5 Zeolite. V.S.Nayak, J.B.Moffat: Journal of Physical Chemistry, 1988, 92[25], 7097–102

 

Table 65

Diffusion Parameters for Alcohols in H-ZSM-5 at 274 to 338K

 

Alcohol

Do(cm2/s)

E(kJ/mol)

n-butanol

2.60 x 10-7

15.9

isobutanol

1.80 x 10-7

25.7

n-pentanol

5.30 x 10-7

22.7

n-hexanol

1.47 x 10-6

27.9

n-heptanol

3.37 x 10-6

33.3

n-octanol

3.83 x 10-5

40.9

n-butylamine

1.56 x 10-6

26.4

 

Table 66

Diffusion of Alcohols in ZSM-5

 

Alcohol

Temperature(K)

D(cm2/s)

methanol

293

5.75 x 10-10

methanol

308

8.28 x 10-10

methanol

323

1.13 x 10-9

ethanol

293

1.32 x 10-10

ethanol

308

2.35 x 10-10

ethanol

323

4.06 x 10-10

1-propanol

293

5.90 x 10-11

1-propanol

308

1.32 x 10-10

1-propanol

323

2.35 x 10-10

1-butanol

293

4.50 x 10-11

1-butanol

308

7.40 x 10-11

1-butanol

323

1.11 x 10-10

2-methyl-2butanol

293

1.50 x 10-11

2-methyl-2butanol

308

2.80 x 10-11

2-methyl-2butanol

323

5.20 x 10-11

1-hexanol

293

8.00 x 10-12

1-hexanol

308

1.90 x 10-11

1-hexanol

323

3.30 x 10-11