Spin conversion of hydrogen using supported iron catalysts at cryogenic temperature

• In situ FTIR spectroscopy for spin conversion of hydrogen.
• Ortho to para hydrogen spin conversion at cryogenic temperature.
• Supported iron oxide catalysts are active at low temperature.
• The most active catalyst was 10–20 wt% iron oxide supported on alumina.

Alumina-supported iron oxides have been prepared by incipient wetness impregnation method and employed for orthohydrogen to parahydrogen spin conversion at cryogenic temperature. These materials were characterized using a series of characterization techniques such as SEM, XRD, Raman and in situ FTIR spectroscopy. The spin conversion was investigated at low temperature by a batch mode of operation. The in situ FTIR spectra were collected in a transmission mode to obtain the spin conversion. While the iron oxide was highly dispersed over alumina support at low loading percent, a rodlike crystallite of iron oxide was formed at high loading percent. The 10 and 20 wt% iron oxides on alumina were proved to be the most active catalysts. The spin conversion process was very slow and time-dependent. It was concluded that the spin conversion was a function of various factors including the iron oxide loading percent, calcination temperature, and different supports.

In situ FTIR system for the spin conversion of liquid phase orthohydrogen to parahydrogen.Figure optionsDownload as PowerPoint slide