Effect of Cu/HZSM-5 sorbents with different Si/Al ratios on the adsorption and oxidation performance of H2S

Abstract

This study employed a wet impregnation method to synthesize five types of Cu/HZSM-5 adsorbents with Si/Al ratios of 25, 50, 85, 200, and 300, used for the removal of H2S in low-temperature, low-oxygen environments. The impact of different Si/Al ratios on the adsorption oxidative performance of Cu30/HZSM-5–85 adsorbents was investigated. According to the performance test results, Cu30/HZSM-5–85 exhibited the highest breakthrough capacity, reaching 231.75 mg H2S/gsorbent. Cu/HZSM-5 sorbent maintains a strong ability to remove H2S even under humid conditions and shows excellent water resistance. XRD, BET, and XPS results revealed that CuO is the primary active species, with Cu30/HZSM-5–85 having the largest surface area and highest CuO content, providing more active sites for H2S adsorption. H2-TPR and O2-TPD results confirmed that Cu30/HZSM-5–85 sorbent exhibits outstanding redox properties and oxygen storage capacity, contributing to excellent oxygen transferability in the molecular sieve adsorption-oxidation process. With notable characteristics such as a large surface area, high desulfurization efficiency, and water resistance, Cu30/HZSM-5–85 sorbents hold significant importance for industrial applications.