Cu–Cr–O Functionalized ETS-2 Nanoparticles for Hot Gas Desulfurization

Engelhard Titanium Silicate-2 (ETS-2), a sodium nanotitanate, was surface functionalized by ion exchanging the solid with copper and chromium ions. The ability of this bi-metallic adsorbent to remove H₂S at elevated temperatures was assessed using a dynamic breakthrough system and contrasted against an analogous mixed metal oxide, Cu–Cr–O. Unlike Cu–Cr–O, the H₂S capacity for CuCr-ETS-2 remains unchanged from 350 °C up to 950 °C. Using ETS-2 as a support for the metals increased the adsorbents surface area and improved its sulfur capacity from 35 mg H₂S/g for Cu–Cr–O to 61 mg H₂S/g adsorbent for CuCr-ETS-2. The consistent presence of Cu₉S₅ on the sulfided adsorbents suggests that chromium effectively stabilizes the copper against reduction to metallic copper up to temperatures as high as 950 °C.