1-Butene metathesis over Mo/mordenite-alumina catalyst: Effect of sodium exchange degree in mordenite zeolite

A series of Mo/mordenite-alumina catalysts with progressive sodium exchange degrees in mordenite were prepared and their performance in 1-butene metathesis reaction was evaluated. Significant variations in product distribution and catalytic activity were observed when the exchange degree of mordenite changed. As revealed by NH3-TPD and 1H MAS NMR results, the acid site density and distribution over the catalysts were directly related to the degree of ion-exchange of sodium in mordenite. The change of support acidity led to different anchoring modes and dispersion of Mo species on the support which further resulted in the different reduction behavior of Mo species under olefin atmosphere. A good correlation between product distribution and properties of the catalysts was proposed.

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► 1-Butene metathesis product distribution could be tuned through changing the sodium exchange degree of mordenite.
► 1-Butene self-metathesis dominates on the catalyst with low sodium exchange degree due to the limitation of 1-butene isomerization.
► High propene yield of 27.4 mol% is obtained on 6Mo/HMOR–Al2O3.
► Anchoring modes and dispersion of Mo species are closely related to the sodium exchange degrees of the support.