Study on the performance and sulfur tolerance mechanism of Pd/beta zeolite in catalytic combustion of toluene

Based on the method of quantitative pyrolysis of ammonium sulfate, sulfur tolerance of Pd/beta zeolite in catalytic conversion of toluene was explored in this paper. Changes in pore structure, valence, acidity, oxidation, and adsorption/desorption behavior were investigated in detail through XRD, N2 adsorption, HRTEM-EDS, XPS, H2-TPR, and NH3-TPD before and after sulfur poisoning. The results proved the structural stability of Pd/beta zeolite in the process of sulfur poisoning. Combined with FT-IR and ICP characterization results, the possible sulfur poisoning process and the intrinsic sulfur tolerance mechanism of Pd/beta zeolite were revealed: Active PdO/Pd reacted with sulfur species to produce inactive PdSO4 was regarded as a major cause of partial deactivation of Pd/beta zeolite. AlO4 units in beta zeolite were likely to combine with sulfur species to obtain Al2(SO4)3 and generate more acidic sites, and SiO4 units in beta zeolite were structurally stable enough to resist sulfur corrosion, guaranteeing the stability of the catalyst. The catalyst catalytic performance was not seriously affected after deep sulfur poisoning, exhibiting good resistance to sulfur poisoning.& COPY; 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Based on quantitative pyrolysis of ammonium sulfate, this paper explores the sulfur tolerance of Pd/beta zeolite in the catalytic conversion of toluene. The changes in pore structure, valence, acidity, oxidation, and adsorption/desorption behavior were investigated through various methods. The results reveal the structural stability of Pd/beta zeolite during sulfur poisoning and provide insights into the sulfur poisoning process and the intrinsic sulfur tolerance mechanism of Pd/beta zeolite.