<prompt> Translate the following text to EnglishSCR catalyst ni sehemu muhimu ya mfumo wa SCR ambayo hutengenezwa ulimwenguni kote na baadhi ya makampuni makubwa zaidi ulimwenguni.  <response>: SCR catalyst is a critical part of the SCR system that is manufactured on a worldwide basis by some of the largest companies in the world. 