What reagent is used in the Rosenmund reduction?

Rosenmund reaction or Rosenmund reduction is a chemical reaction in which the acid chlorides are converted into aldehydes. The reactant in the Rosenmund reaction is acid chloride, and it is reacted with hydrogen in the presence of palladium supported over barium sulfate so, the formation of aldehyde will take place and hydrochloric acid is also produced. The reaction is given below: 푅−퐶푂−퐶푙 퐻2+푃푑−퐵푎푆푂4 → 푅−퐶퐻푂