ZnO-CuO nanoparticles supported on activated carbon for biogas purification from H2S at room temperature

Novel sorbents for reactive adsorption of H2S from biogas at room temperature were prepared by dispersing Zn and Cu oxides nanoparticles onto a commercial activated carbon at fixed total metal loading (10%wt.) and Cu:Zn atomic ratios ranging from 0:1 to 1:1. The functionalized sorbents showed a significantly larger adsorption capacity with respect to the raw activated carbon, and a high utilization factor of the active phase increasing with Cu loading. This was associated to the high dispersion of the metal oxides and the positive interaction with the support. Temperature Programmed Desorption (TPD) of H2S and SO2 from saturated sorbents showed that H2S adsorption was coupled with oxidation phenomena, leading to the formation of metal sulphates apart from metal sulphides and/or elemental sulphur.