Purification of Hydrogen from CO with Cu/ZSM-5 Adsorbents

Molecules

Kristina Chakarova¹  Radoslav Kefirov¹  Stanislava Andonova¹  Videlina Zdravkova¹  Elena Ivanova¹  Mihail Mihaylov¹  Nikola Drenchev¹  Rositsa Kukeva¹  Radostina Stoyanova¹  Konstantin Hadjiivanov¹ 

[1] Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria;

关键词: adsorption;    breakthrough curves;    carbon monoxide;    Cu/ZSM-5;    FTIR spectroscopy;    hydrogen purification;   

DOI  :  10.3390/molecules27010096

来源: DOAJ

【 摘 要 】

The transition to a hydrogen economy requires the development of cost-effective methods for purifying hydrogen from CO. In this study, we explore the possibilities of Cu/ZSM-5 as an adsorbent for this purpose. Samples obtained by cation exchange from aqueous solution (AE) and solid-state exchange with CuCl (SE) were characterized by in situ EPR and FTIR, H₂-TPR, CO-TPD, etc. The AE samples possess mainly isolated Cu²⁺ cations not adsorbing CO. Reduction generates Cu⁺ sites demonstrating different affinity to CO, with the strongest centres desorbing CO at about 350 °C. The SE samples have about twice higher Cu/Al ratios, as one H⁺ is exchanged with one Cu⁺ cation. Although some of the introduced Cu⁺ sites are oxidized to Cu²⁺ upon contact with air, they easily recover their original oxidation state after thermal treatment in vacuum or under inert gas stream. In addition, these Cu⁺ centres regenerate at relatively low temperatures. It is important that water does not block the CO adsorption sites because of the formation of Cu⁺(CO)(H₂O)_x complexes. Dynamic adsorption studies show that Cu/ZSM-5 selectively adsorbs CO in the presence of hydrogen. The results indicate that the SE samples are very perspective materials for purification of H₂ from CO.

【 授权许可】

Unknown