title: Communication: A novel method for generating molecular mixtures at extreme conditions: the case of hydrogen and oxygen.
abstract: We have successfully created a segregated mixture of hydrogen and oxygen at high pressure in a diamond anvil cell using hard x-ray photochemistry. A keyhole (two holes connected by an opening) sample chamber was created in a metallic gasket to support two segregated powders of ammonia borane and potassium perchlorate, respectively, in each hole at a pressure of ~5.0 GPa. Both holes were separately irradiated with synchrotron hard x-rays to release molecular oxygen and molecular hydrogen, respectively. Upon irradiation of the first KClO4-containing hole, solid reddish-orange O2 appeared in the region of irradiation and molecular oxygen was found to diffuse throughout the entire sample region. The second ammonia borane-containing hole was then irradiated and H2 was observed to form via Raman spectroscopy. Water also was observed in the ammonia borane-containing hole and possibly (in the form of ice VII) in the second hole. This unique experiment demonstrates the ability to easily create solid mixtures of simple molecular systems via x-ray irradiation and then react them via further irradiation which will aid the study of chemistry under extreme conditions.
authors.affiliation: High Pressure Science and Engineering Center (HiPSEC) and Department of Physics, University of Nevada Las Vegas (UNLV), Las Vegas, Nevada 89154-4002, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Pravica
authors.affiliation: High Pressure Science and Engineering Center (HiPSEC) and Department of Physics, University of Nevada Las Vegas (UNLV), Las Vegas, Nevada 89154-4002, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sneed
authors.affiliation: High Pressure Science and Engineering Center (HiPSEC) and Department of Physics, University of Nevada Las Vegas (UNLV), Las Vegas, Nevada 89154-4002, USA.
authors.forename: Melanie
authors.initials: M
authors.lastname: White
authors.affiliation: High Pressure Science and Engineering Center (HiPSEC) and Department of Physics, University of Nevada Las Vegas (UNLV), Las Vegas, Nevada 89154-4002, USA.
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Wang