| 摘要 |
A catalyst comprises 48.5-53.5 wt.% CaO; 42.5-46.5% P205; 0.05-1.0 (pref. 0.02-0.3)% Cl; 0.005-3.0(pref. 0.02-0.3)% B203; and water as balance to 100%. A 1,3 dioxane is catalytically converted into isoprene using the above catalyst. The catalyst is generally useful for mfr. of isoprene from isobutylene and formaldehyde, and in alcohol dehydration reactions, esp. for decompsn. of 4,4 dimethyl-1,3 dioxane to isoprene. It provides higher activities at lower temps. than known catalysts, e.g. a 40% increase in 1,3 dioxane decomposition at 280 deg.C; higher selectivity by about 12 mole%, normally giving selectivity about 87-88%; and catalyst life up to 6 times higher than known catalysts. |
