Jan Hendrik de Boer (19 March 1899 – 25 April 1971) was a Dutch physicist and chemist.
De Boer was born in
Ruinen, now De Wolden, and died in The Hague. He studied at the  University of Groningen and was later employed in industry.
Anton Eduard van Arkel, de Boer developed a chemical transport reaction for titanium, zirconium, and hafnium known as the crystal bar process. In a closed vessel the metal reacts with iodine at elevated temperature forming the iodide. At a tungsten filament of 1700 °C the reverse reaction occurs, and the iodine and the metal are set free. The metal forms a solid coating at the tungsten filament and the iodine can react with additional metal, resulting in a steady turnover. 
M + 2I
2 (>400 °C) → MI 4 MI
4 (1700 °C) → M + 2I 2
De Boer became a member of the
Royal Netherlands Academy of Arts and Sciences in 1940, and foreign member in 1947. 
References [ edit ]
^ van Arkel, A. E.; de Boer, J. H. (1925). "Darstellung von reinem Titanium-, Zirkonium-, Hafnium- und Thoriummetall". Zeitschrift für anorganische und allgemeine Chemie. 148 (1): 345–350. doi: 10.1002/zaac.19251480133.
^ "J.H. de Boer (1899 - 1971)". Royal Netherlands Academy of Arts and Sciences . Retrieved . 17 July 2015