Search

CO oxidation at mild condition is significant for industrial process but still challenging nowadays, especially for the non-noble metal catalysts. The preparation method significant affect the catalytic activity of the catalyst. Comparing with cobalt supported on tantalum oxide prepared by impregnation method, Co/Ta2O5 prepared by deposition–precipitation method with urea in this study has smaller particle size, higher specific surface area and better redox properties, and these features make the catalyst exhibit higher catalytic activity for CO oxidation at mild condition. 90% CO conversion was achieved at 130 ℃, and CO was fully converted at 150 ℃. The XPS and DRIFTs results show that Co/Ta2O5 has more oxygen vacancies, and the absorbed CO will react with oxygen. The study may provide a new thought for the preparation of catalysts with high activity at mild condition. [ABSTRACT FROM AUTHOR]

BACKGROUND Hydrolysis of polysaccharides is a key step in biorefineries processes. In this study, an economic and green approach was developed to hydrolyze soluble polysaccharides (starch, inulin, etc.) into monosaccharides by a natural clay of attapulgite (ATP) modified with H2SO4(ATPS), and the catalysts were characterized by Fourier Transform Infrared Spectroscopy (FT‐IR), Pyridine FTIR Spectroscopy (pyridine‐FTIR), Temperature Programmed Desorption of Ammonia (NH3‐TPD), Thermo‐Gravimetric/Differential Thermal Analyze (TG‐DTA). The hydrolysis of different substrate over ATP‐S was evaluated. RESULTS: After H2SO4 modification, the total acid sites of the catalyst ATP‐S increased from 65.33 to 109.46 umol g–1, and the surface area also increased from 81.4 to 137.3 m2 g–1. ATP‐S shows excellent activity and stability for polysaccharides hydrolysis in aqueous system. As for inulin as reactant, 98.5% of hydrolysis ratio was obtained at the moderate temperature of 95 °C for 210 min, and 75.8% hydrolysis ratio was achieved for starch. More importantly, there is no apparent decline of the catalytic activity after 4 recycles in aqueous system. In addition, the kinetic analysis was carried out, and the activation energy of the substrates were calculated. CONCLUSION: Compared with other hydrolysis processes involving enzymes and homogeneous catalysis, the process in this paper is more cost‐efficient and environmentally friendly, and it can easily be scaled‐up and implemented in chemical and bio‐based industries. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]