(US5041408-A)      Shaped catalyst (or precursor) particles (A) consist of a Ca aluminate cement and 10-70 wt.% Ni and/or Co, expressed as divalent oxide having (B) a porosity 25-50% comprising at least 30, (pref. 40-70) vol.% pores of dia. 15-35 nm and less than 40 vol.% pores of dia. above 35 nm. The particles pref. have a bulk density 0.8-1.5 g/cm3. The catalyst contains 0.2-10 wt.% Fe2O3. The oxides are present as a (hydrated) oxide of a higher than divalent state. Pref. the shaped particles are extrudates.    ADVANTAGE -   A cheaper catalyst than known ones. The active material is readily available to the reactants.    (6pp)    (US5149893-A)      Process comprises contacting an effective catalyst with a feed stream of gaseous H2 and unsatd. hydrocarbon. Catalyst is prepd. from a precursor (I) comprising Ca aluminate cement and an oxide of ni and/or Co. (I) contains 10-70wt.% MO, and has 25-50% porosity with at least 30% of pore vol. comprises 15-35nm pores, and less than 40% of pore vol. comprises pores of greater than 35nm.    Feed stream pref. comprises gaseous H2 and benzene.    USE/ADVANTAGE -   For treatment of effluents contg. oxidising ions e.g. hypochlorite prior to discharge into rivers, lakes, or estuaries.    (US5220110-A)      A process for the decomposition of an oxidising agent in an aq. soln. having a pH above 7 comprises: contacting the aq. soln. with a fixed catalyst bed of shaped particles comprising at least one oxide of a Group VIII metal M such a nickel or cobalt. the improvement comprises the catalyst particles comprising 10-70 wt.% of the Group VIII metal oxide (expressed as the divalent oxide MO), and a calcium aluminate cement, and having a porosity in the range 25-50%. At least 30% of the pore volume is in the form of pores of size in the range 15-35 nm and less than 40% of the pore volume is in the form of pores of diameter greater than 35 nm.    USE/ADVANTAGE -   The improvement provides a catalyst of increased activity and/or service life. The particles are used to catalytically decompose oxidising agents including hypohalites.    (JP2584527-B2)      Shaped particles (I) of use as catalyst or catalyst precursor comprise (a) calcium aluminate cement, and (b) at least one oxide of nickel and/or cobalt, 10-70 wt.% or (I) expressed as NiO or CoO; Particles (I) have porosity 25-50%; at least 30% of the pore volume is in pores of 15-35 nm, and less than 40% in pores of dia. greater than 35 nm.    A preferred method comprises precipitating a Co or Ni cpd., e.g. by adding an alkali metal carbonate to an aq. solution of the nitrate, washing the ppte., opt., mixing with a finely divided diluent material, e.g. magnesia or clay, drying, and calcining at 400-550 deg.C. The oxide material formed is mixed with the cement, opt. with a processing agent, e.g. a little water, a stearate or graphite, and formed into pellets. The cement may comprise calcium mono-aluminate, tricalcium aluminate, pentacalcium aluminate, tricalcium penta-aluminate or dodecacalcium hepta-aluminate. The presence of iron oxide in the cement can in some application be tolerated, or can even by beneficial. A method of pelleting to obtain the required porosity comprises use of a pellet mill of the type used for pelleting animal feedstuffs, wherein the mixture is extruded and extrudate cut with a doctor knife to required length. The pellets are then hardened by contact with steam.    USE/ADVANTAGE -   (I) is used (i) as a fixed bed catalyst for decomposition of an oxidising agent in a fluid medium, e.g. an aq. medium of pH above 8. The oxidising agent may be hypochlorite ions in an effluent prior to discharge of the latter into river, lake or estuary; and (ii) to reduction to a hydrogenation catalyst, of use for hydrogenation of carbon oxides to methane, and hydrogenation of aromatics, e.g. benzene to cyclohexane. The active material in (I) is readily accessible, and the cement can stand highly alkaline conditions.