Investigating the performance of a Rh metal catalyst in hydrogen–deuterium exchange reactions in methane for application in low-temperature membrane separators

• We investigated the catalytic efficiency of different noble metal catalysts.
• We determined that Rh was the most effective noble metal catalyst.
• We characterized the optimal conditions of Rh catalyst for H–D exchange in methane.
• The results can be applied to the separation of H isotopes in plasma ash and gases.

The development of safe, efficient, and cost effective methods to recover waste components of deuterium–tritium (D–T) plasma reactors, including hydrogen and methane, has attracted much interest in the scientific community. Typically, membrane separators are used for this process, although several problems occur when performing separations at higher temperatures. The application of noble metal catalysts may improve the reaction dynamics and allow the separation process to occur at lower temperatures. In this paper, a series of noble metal catalysts were prepared by a traditional dipping method. Based on an analysis of catalytic performance, the Rh/Al2O3 catalyst was determined to be the most suitable for the exchange of hydrogen and deuterium in methane. The catalyst was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and temperature programmed reduction analyses. The effects of the metal loading and experimental conditions were also investigated.