Page 268 - Principles of Catalyst Development

APPENDIX 6

Laboratory Recipes

1. SINGLE OXIDES

1.1. Alumina Gel (A Support and Dehydration Catalyst)

Dissolve 1000 g ofCP AICI 3 6H 20 in 10,000 cm of H 20. Prepare an aqueous
3
ammonia solution by adding 840 cm of concentrated ammonia hydroxide
3
(about 30% NH 3 ) to 1450 cm of H 20. Add the ammoniacal solution to the
3
AICh solution until the pH is about 8. Allow the precipitate to settle and
filter with a Buchner funnel. Wash five times by decantation with 5 cm of
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concentrated ammonia in 5000 cm of H 20. Allow the precipitate to settle
3
and filter with a Buchner funnel. By the end of the fifth wash, the precipitate
is very difficult to settle since it has started to peptize. If a water wash
containing no ammonia is used, peptization begins even during the first
wash.
Dry the washed filtrate in an oven for several hours at 100-150°C. Then
calcine overnight at about 550°C in a muffle furnace.

1.2. Silica Gel (A Support)
Prepare two solutions. Solution A is 500 cm 3 of water glass
(Si02/Na20 = 3.22) in 1000 cm of H2 0. Solution B is 245 cm of 4 N HCI
3
3
plus 300 em) of H2 0. Cool both solutions to about 5°C, then add solution
A to solution B with vigorous mechanical agitation. Pour into a flat tray.
The resulting sol has a pH of about 6 and a gel time of 2 miri. The gel
will be stiff enough to cut into cubes within 30-60 min. Transfer the cubes
to a Buchner funnel as soon as possible. Treat immediately with 1 N HCI
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