Effect of Morphology Control of Hexaniobate Nanotubes on their Acid Characteristics and Ethyl Mercaptan Removal in Light Alkane

Organic sulfide usually exists in light alkane such as natural gas, biogas, oilfield gas, etc. Due to its toxicity, flammability, and corrosivity, a series of environmental and safety problems will be caused. Physical adsorption with adsorbent is one of the dry desulfurization methods, which has the characteristics of mild conditions, no by‐products, and simple regeneration. Herein, the adsorbent protonated H4Nb6O17 nanotubes (HNT) were constructed by a new spray method. The morphology, skeleton structure, surface hydroxyl groups, and the Brønsted acid sites properties of the as‐prepared samples were characterized and analyzed in detail. The adsorption, separation, and recycling performance were evaluated by the probe compound ethyl mercaptan (Et‐SH) in CH4. The results show that H4Nb6O17 nanotubes prepared by a spray method with improved morphology have better adsorption properties for ethyl mercaptan in methane than that of the sample prepared by traditional flocculation methods. The results suggest that the spray technology brings about high dispersion of nanotube aggregation, small tube diameter, and the enhancement of Brønsted acid. These characteristics will lead to higher adsorption and removal capacity of ethyl mercaptan. This work is also helpful to explain the relationship between structure and acidity in niobate nanomaterials, and provides new idea for the construction of 1D nanomaterials. Compared with the H4Nb6O17 nanotubes prepared by traditional method, the adsorption performance of nanotubes prepared by spray method to ethyl mercaptan from mixed gas is significantly improved. The higher curling degree of nanotubes resulting in a stronger Brønsted acid site. The high desulfurization adsorption performance may be related to surface acidity and spatial confinement effect.