Tollens attended school at the Gelehrtenschule des Johanneums in Hamburg where he was influenced by his science teacher, Karl Möbius.

He finished in 1862 and began studying chemistry in Göttingen in Wöhler's laboratory, then supervised by Friedrich Konrad Beilstein and Wilhelm Rudolph Fittig.

He later worked with Charles-Adolphe Wurtz in Paris and, for 11 months, as chief of the chemical laboratory at the University of Coimbra in Portugal.

[1] Unable to resist the call of his former professor Wöhler, Tollens returned to Göttingen in 1872 and there he remained in various positions until he died in 1918.

It was during this final time in Göttingen that he started his work on carbohydrates, which yielded structures of several sugars, the Tollens' reagent, and most of his publications.