Facile synthesis of cuprous chloride/copper chloride hydroxide composites for reactive removal of hydrogen sulfide at room temperature

Abstract

In this work, a self-assembly method is developed to synthesize a series of cuprous chloride/copper chloride hydroxide composites (CCCCHs). The hydrogen sulfide (H2S) removal performances of these materials are investigated under the conditions of 25 °C, 1 atm and the inlet H2S concentration of 250 ppm in a gaseous N2 mixture with a flow rate of 40 mL min−1. It is demonstrated that the intermediate product of Cu by Fe reduction can react with CuCl2 to form cuprous chloride (CuCl). Then, CuCl2 and H2O are self-assembled on the surface of CuCl to generate the shell layer of copper chloride hydroxides (CCHs). When the molar ratio of CuCl2 to Fe is 4, the CCCCHs show the largest H2S adsorption capacity of 259.5 mg g−1 because CuCl core is almost covered by CCHs overlayers. Based on extensive results of XRD, SEM, TEM, EDS, XPS and FTIR analyses, the sulfidation reaction mechanism of CCCCHs can be revealed. When react with H2S, the CCHs surface is decomposed to generate CuCl2·2H2O and Cu2+ is reduced to Cu+, which is accompanied by the oxidation of H2S to form elemental sulfur and sulfate. During the decomposition process of CCHs, sulfidation reaction can penetrate deeply into the adsorbent particles, and the H2S treatment capacity of adsorbent is substantially improved.