Abstract: A three-way catalyst of improved efficiency suitable for simultaneously oxidizing both gaseous hydrocarbons and carbon monoxide, while reducing nitrogen oxides is disclosed. The three-way catalyst includes alumina, a platinum group metal and a rare earth metal oxide having deposited thereon in intimate contact therewith a p-type metal oxide.

Abstract: A hydrogen treating catalyst comprising alumina, 3 to 7% by weight of nickel calculating as NiO and 10 to 20% by weight of molybdenum calculating as MoO.sub.3, which has a total pore volume of 0.55 to 1.0 ml/g, an average pore diameter of 50 to 250 .ANG., and factor P of 3 to 4, wherein the volume of pores having a diameter of larger than the average pore diameter+10 .ANG. and smaller than the average pore diameter+500 .ANG. is 10 to 30% of the total pore volume in catalyst pore distribution, wherein the factor P is represented by the following formula:P=PD/Swherein PD represents an average pore diameter measured by a mercury porosimeter which is the pore diameter (.ANG.) corresponding to the pressure at which 1/2 of the total pore volume is saturated with mercury, and S represents a proportion (%) of volume of pores in a range of PD.+-.5 .ANG..

Abstract: For making low density alumina or silica-alumina beads as catalyst support particles for auto-exhaust catalysts, hollow glass spheres of very small diameter are incorporated in the alumina powder mix before it is formed into beads and calcined. The beads may be finished with a surface coat of alumina without the microspheres to improve resistance to abrasion. Preferred beads are made with rehydratable alumina powder.

Abstract: Aggregates having the amphora shape are produced by a process comprising dropping droplets of a slurry capable of being chemically gelled or solidified into a container containing a middle liquid phase capable of chemically gelling or solidifying the slurry, an upper liquid phase above the middle liquid phase and a lower liquid phase below the middle liquid phase, the components of the slurry exhibiting substantially no solubility in the upper and lower phases.