An in situ powder diffraction cell for high-pressure hydrogenation experiments using laboratory X-ray diffractometers

An in situ diffraction cell is presented which has been designed and constructed for in-house powder diffraction experiments under high gas pressures up to 30 MPa. For a proof of principle, the in situ cell has been tested for several hydrogenation experiments under elevated pressures and temperatures. LaNi₅ was chosen as an example for hydrogenation, applying simultaneously 5.5 MPa H₂ pressure at a temperature of 423 K. For testing the high-pressure-temperature suitability of the in situ cell, pressure-temperature experiments up to 14 MPa at 373 K were performed, studying the rehydrogenation of NaH and Al to NaAlH₄. The experimental setup enables recording of in situ X-ray diffraction data on laboratory instruments with short data acquisition times at elevated hydrogen pressures and temperatures.