A comparison of γ-Al2O3-supported deoxo catalysts for the selective removal of oxygen from high-concentration hydrogen streams

• Published in: International journal of hydrogen energy 2024-01, Vol.51, p.396-409
• Main Authors: Kim, Taejun, Balla, Putrakumar, Shin, Daeseob, Kim, Sungtak
• Format: Article
• Language: English
• Subjects: Deoxo-catalyst; H2 purification; H2 safety; H2–O2 recombination; Pd catalyst
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2023.06.227

The removal of oxygen from hydrogen using a catalytic reaction of H2–O2 recombination is considered an essential technology for improving H2 purity and safety in green hydrogen production. Previously research mainly has been conducted on removing H2 from O2 in nuclear power plants. Herein, in line with the era of hydrogenation, the performance of monometallic (Pd, Pt, Cu, Ni) catalysts for removing O2 from high-concentration H2 streams was investigated. The catalysts were prepared by the wet impregnation method and characterized. The Pd/Al2O3 showed the best performance, removing up to 99.99% of O2 from H2 stream. The Pt/Al2O3 catalyst had a high deoxo performance, but its deactivation was observed at low metal contents. The Cu/Al2O3 and Ni/Al2O3 catalysts removed less than 50% O2 for all metal contents. The Pd/Al2O3 catalyst maintained its ability to remove 99.95% of O2 in H2 stream for 500 h on stream. Deactivation of the Pd/Al2O3 catalyst was caused by an additional reduction, resulting in the structural rearrangement of Pd with surface O2. [Display omitted] •O2 in high concentration H2 was removed H2–O2 recombination reaction by deoxo catalyst.•Pd, Pt catalysts exhibited more than 99.9995% H2 purity within 60 min under continuous streams.•Pd catalyst maintained O2 concentration less than 10 ppm for 500 h continuous reaction.•Deoxo performance is expected to be related to surface oxygen vacancies.