Efficient Pt/KFI zeolite catalysts for the selective catalytic reduction of NOx by hydrogen
Hong He , Ligang Zhang , Yulong Shan , Zidi Yan , Zhongqi Liu , Yunbo Yu
DOI:10.1016/j.jes.2023.03.004
Received January 19, 2023,Revised , Accepted March 02, 2023, Available online March 09, 2023
Volume 36,2024,Pages 102-111
Aiming at purification of NOx from hydrogen internal combustion engines (HICEs), the hydrogen selective catalytic reduction (H2-SCR) reaction was investigated over a series of Pt/KFI zeolite catalysts. H2 can readily reduce NOx to N2 and N2O while O2 inhibited the deNOx efficiency by consuming the reductant H2. The Pt/KFI zeolite catalysts with Pt loading below 0.1 wt.% are optimized H2-SCR catalysts due to its suitable operation temperature window since high Pt loading favors the H2-O2 reaction which lead to the insufficient of reactants. Compared to metal Pt0 species, Ptδ+ species showed lower activation energy of H2-SCR reaction and thought to be as reasonable active sites. Further, Eley-Rideal (E-R) reaction mechanism was proposed as evidenced by the reaction orders in kinetic studies. Last, the optimized reactor was designed with hybrid Pt/KFI catalysts with various Pt loading which achieve a high NOx conversion in a wide temperature range.
