After obtaining a Ph.D in physical chemistry from McGill University in Montréal in 1989, JH was a postdoctoral fellow in the high pressure inorganic chemistry group of David Adams at the University of Leicester for two years. JH joined the CNRS as a researcher in 1992 in the field of high pressure effects in framework and simple oxides. This work is in the general areas of crystallography and materials synthesis at high pressure. Over the past ten years, a significant part of this research has been focussed on zeolites, including guest insertion, high pressure amorphisation and nanocomposite synthesis. JH has published more than 180 research papers in these areas.