Abstract
SAPO-11 molecular sieve is a promising candidate for preparation of hydrocarbon-based biofuels. Herein, two typical acids including citric acid (CA) and nitric acid (NA) are used to modify SAPO-11. The results show that the acid concentration was within the range of 0.05–1.0 mol L−1, SAPO-11 maintained a complete crystal framework structure, and more (002) crystal planes were exposed. The specific surface area, pore diameter and acid content of molecular sieve by acid modification are significantly higher than those of the fresh SAPO-11. The pore size increased from 7 nm to 17 and 18 nm, an increase of the total acid from 104 μmol g−1 to 174 and 162 μmol g−1, respectively, when SAPO-11 was treated by CA with 0.5 mol L−1 and NA with 0.3 mol L−1. Pt–Sn/SAPO-11-CA-0.5 showed the best catalytic activity with selectivity of C15–C18 alkanes of 95.8% and iso-alkanes of 33.1%. Additionally, the deoxygenation ability of Pt–Sn/SAPO-11-CA-0.5 decreased 30% after running 1200 h. Using propionic acid (PA) as the model probe molecule, the DFT reveals steps of the hydrodecarbonylation pathway of PA absorbed on the Pt (111) plane as below: CH3CH2COOH*→CH3CH2CO*→CH3CHCO*→CH3CCO*→CH3C*+CO*, and the rate-limiting step is CH3CH2COOH*→CH3CH2CO*+OH*.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
