Hydrothermal preparation of hierarchical SAPO-34 constructed by nano-sheets using rapeseed pollen extract as water and its CO2 adsorption property

• Hierarchical SAPO-34 constructed by nano-sheets is prepared.
• Aqueous rapeseed pollen extract is used to prepare the synthesis solution.
• The hierarchical SAPO-34 exhibits a large surface area.
• It can adsorb CO2 with high capacity and fast adsorption kinetics.

Herein we report a biosynthesis route to prepare hierarchical SAPO-34 constructed by numerous nano-sheets. Rapeseed pollen extract was used as water to prepare the synthesis solution, which underwent hydrothermal synthesis to obtain the hierarchical SAPO-34. The product is characterized by XRD, FT-IR, SEM, N2 adsorption–desorption and TG analysis. The hierarchical SAPO-34 shows a distinctive morphology with curly nano-sheets and gaps between nano-sheets, forming a blooming flower-like structure. Its specific surface area is 683 m2 g−1. The effect of the content of rapeseed pollen suspension was examined. Increasing in the content leads to the formation of the hierarchical SAPO-34 constructed with curlier and much more numbers of nano-sheets. The formation process of SAPO-34 was investigated and a possible formation mechanism was proposed. Such hierarchical SAPO-34 exhibits a high CO2 adsorption capacity of 2.77 mmol/g at 100 kPa and the CO2/CH4 ideal separation factor of 8.2. It takes 6.1 min for CO2 to reach the adsorption equilibrium, which is faster than that of conventional SAPO-34, possibly due to such nano-sheet-constructed fine structure.

A novel hierarchical SAPO-34 constructed by numerous nano-sheets is prepared by hydrothermal treatment through a biosynthesis route. Rapeseed pollen extract is used as water to prepare the SAPO-34 synthesis solution. The hierarchical SAPO-34 shows a large specific surface area, a high CO2 adsorption capacity and fast diffusion rate.Figure optionsDownload as PowerPoint slide