His father, Miguel, was a spectroscopist and his mother, Jimena, was a teacher and co-founder of the Colegio Estudio, a children's school in Madrid where Catalán was a pupil for four years.
He coordinated a large-scale project, el Romancero panhispánico (the Pan-Hispanic Ballad), which aimed to collect and preserve texts of this type and their variants.
He proposed the distinction between two varieties of Spanish: Catalán was the owner of the Archivo del Romancero (Ballad Archive), which covers materials and work of philological and historical research.
This contains all files and scientific material used by Pidal to prepare, among others, his magnum opus, Historia de la Lengua Española, which was published posthumously in 2005 and again as a second edition in 2007.
This includes scientific and institutional correspondence between Pidal and both researchers and key figures in both Spanish and international culture from the late nineteenth century until the first half of the twentieth, such as Gaston Paris, Américo Castro, and Antonio Solalinde, among others.
This is a documentary collection of investigations that accompanied Pidal's work, such as files from both him and wife on literature, linguistics, history, and literary and historical figures.