Abstract: A catalyst pack (1) for the manufacture of nitric acid by oxidizing ammonia comprises at least one layer (2, 3, 4, 5, 6) of elongate elements made from at least one platinum group metal or alloy and at least one foraminous layer (7, 8) of ceramics material having a coating of one or more platinum group metals or alloys or mixture. In use the catalyst pack has improved conversion efficiencies. The preferred ceramics material comprises either alumina, slicia and boria or zirconia in the form of a cloth.

Abstract: A process for the manufacture of nitric oxide by the oxidation of ammonia using a catalyst (1) comprising platinum in which the ammonia conversion efficiency of the process is improved by the use of a palladium catchment trap (2) in which the conventional layers (8 and 10) of palladium scavenger-wire are adjacent to layers (7, 9 and 11) of interstitial (preferably woven) ceramics material. The preferred ceramics material consists of alumina, silica and boria. Also a catchment trap comprising layers of ceramics material for use in the process.