TERMIUM Plus^®

Fiche 1,  Justifications,  Anglais

Record number: 1, Textual support number: 1 CONT

Acid catalysts are employed in such diverse areas as Friedel-Crafts reactions (qv) and reactions in the presence of clays. The isomerization of n-butane over an aluminum halide-hydrogen catalyst takes place only in the presence of olefins. Friedel-Crafts catalysts, mineral acids ... all act in a similar manner because of their essential acidity. In each case the active catalyst contains a proton; it is a Brönsted acid. ... Catalytic activity of acid catalysts is correlated with surface acidity for different reactions. The Brönsted acidity is necessary for successful catalytic cracking, and the distribution of acid strengths is important.  2, fiche 1, Anglais, - acid%20catalyst

Fiche 1,  Justifications,  Français

Record number: 1, Textual support number: 1 OBS

Dans les réactions de catalyse acido-basique, l'une au moins des étapes est un transfert de proton du catalyseur au substrat S (catalyse acide) ou du substrat au catalyseur (catalyse basique). Le substrat intervient, de ce fait, soit comme base, soit comme acide, et la réaction implique donc un équilibre protolytique.  2, fiche 1, Français, - catalyseur%20acide

Fiche 1,  Justifications,  Espagnol