Deep removal of ultra-dilute H2S for H2 purification using CuCo layered double hydroxide adsorbent

Deep removal of ppm-H2S is critical for H2 quality control due to the increasing demand for ultrahigh-purity H2 in the up-and-coming fuel cell market. Herein, a CuCo layered double hydroxide (LDH) adsorbent with basic surface and high dispersion of active (Cu, Co) metal sites was developed for selective capture of ppm-H2S. The as-synthesized adsorbent enables effective elimination of H2S from 50 to <1 ppm with superior dynamic adsorption capacity of 187 mg-H2S/g-ads, which outperformed the reported benchmark adsorbents. The excellent performance could be attributed to the hollow structure and ultra-thin LDH nanosheets, which endow the high exposure of metal hydroxide sites, and thus facilitating the selective capture of H2S through reactive adsorption. For practical application, the effects of CO2 and H2O on adsorption were also investigated. The excellent H2S adsorption performance demonstrated in this work makes hydroxide a promising adsorbent for removal of ppm-H2S for ultrahigh purity H2 production.