Enhanced selectivity and stability of Pt-Ge/Al2O3 catalysts by Ca promotion in propane dehydrogenation
نویسندگان
چکیده
• Calcium increases Pt-Ge alloy extent by enhancing Ge reducibility. significantly enhances catalyst stability and propylene selectivity. selectively suppresses strong acid sites. Calcium-promoted is less active for coke deactivation, (? d ). Steady state activity increased since Ca decreases ? more than r . The promoting effect of on the catalytic performance Pt 0.5 -Ge 1.5 /Al 2 O 3 during propane dehydrogenation (PDH) reaction was studied using experimental methods kinetic modeling. Different characterization techniques including H -TPR, NH -TPD, C 6 XPS, BET, CO-chemisorption, CO-DRIFT, TGA were used to unravel properties catalysts. Enhanced selectivity (98.5% Vs 96.4% @ 600 °C 24 h TOS) achieved due decrease centers Al along with an increase degree formation upon addition Ca. data conversion vs. time successfully fitted Deactivation Model Residual Activity (DMRA), allowing calculation intrinsic deactivation parameters both For Ca-promoted catalyst, a function 0.05 ?1 residual 0.82 at obtained. Whereas, non-promoted sample, these values 0.22 0.63, respectively. activation energy PDH -CaO slightly higher that unmodified one (74.8 kJ/mol 66.4 kJ/mol) enhanced reduction GeO x species this which alloy, decreasing initial catalyst. However, resistance against promoted invoked explain better in terms steady conditions.
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ژورنال
عنوان ژورنال: Chemical Engineering Journal
سال: 2021
ISSN: ['1873-3212', '1385-8947']
DOI: https://doi.org/10.1016/j.cej.2020.126656