In-situ preparation of Cu-BTC modified with organic amines for H2S removal under ambient conditions

Amine modification is an effective strategy to improve the H₂S removal performance of Cu-BTC. In order to avoid the problem of pore blockage after amine modification in post synthesis impregnation, herein a series of Cu-BTC modified with organic amine adsorbents were prepared via an in-situ one-pot method and the H₂S removal performance under ambient conditions was tested. It is found that the introduced organic amines, depending on the types of amine selected, have a significant influence on the growth of Cu-BTC and its textural properties. The H₂S removal performance on the as-prepared materials suggested that the amine modified samples remarkably improved the H₂S removal capacities with an order of BA-Cu-BTC > TEA-Cu-BTC > TEOA-Cu-BTC > Cu-BTC. Besides the enlarged surface area and the increased mesopores volumes, BA has the advantages of smaller steric hindrance and –NH₂ groups, among which the former increased the accessibility of Cu active sites while the latter acted as additional active sites for H₂S capturing, thus affording BA-Cu-BTC highest breakthrough capacity of 77.3 mg S/g. Overall, this study elaborates the effect of organic amines in-situ modification on the Cu-BTC structure and desulfurization.