He was born to the Jonkheer François Mols (1767–1845), and his wife, Theresa Van de Zanden (1781–1813).
In 1838, he travelled to Egypt and the Middle East in the company of the noted art patron, Charles Stier d’Aertselaer (1770–1847).
Later that year, they were in Egypt at the same time as David Roberts, and worked together, sketching ancient monuments.
After returning through Alexandria, they visited Greece, then crossed to Trieste and made their way through Austria and Germany to Saint Petersburg.
They had four children: Léonie-Marie, who became an art collector and patron, Marie-Clementine, Robert, who also became a painter, and Alexis.