| 摘要 |
Shaped units suitable for use as a catalyst, e.g. for the decomposition of hypochlorite, comprise a compacted particulate mixture of at least one oxide of a Group VIII metal M selected from nickel and cobalt, a calcium aluminate cement, and alumina and/or magnesia, the shaped units having (after ignition in air at 900° C.) a content of a Group VIII metal oxide of 10 to 50% by weight (expressed as the divalent oxide, MO), a calcium oxide content of 1 to 10% by weight, an alumina content by weight that is at least four times the weight of calcium oxide, a total content of alumina plus magnesia of at least 40% by weight, a silica content of less than 1% by weight, and the shaped units having a pore volume in the range 0.2 to 0.5 ml/g and having a pore size distribution such that from 5 to 25% of the total pore volume is in the form of pores of diameter in the range 15 to 35 nm, at least 30% of the total pore volume is in the form of pores of diameter greater than 35 nm, and 10 to 20% of the total pore volume is in the form of pores of diameter greater than 1500 nm.
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