Effects of acid leaching post-treatment on the catalytic performance of MoO3/mordenite-alumina catalysts for 1-butene metathesis reaction

Molybdenum oxide supported on mordenite zeolite-alumina composite is post-treated by nitric acid leaching with varying periods (12–48 h). The post-treated molybdenum catalysts display much higher stability for propene formation in 1-butene metathesis reaction. The evolution of Mo species has been characterized by laser Raman, 27Al MAS NMR and X-ray photoelectron spectroscopy. Characterization results have shown the extraction of aluminum molybdates (Al2(MoO4)3) after acid leaching post-treatment. This structural transformation relates to a transition in coke species on the spent molybdenum catalysts, and leads to the improvement in metathesis stability.

Molybdenum oxide catalysts supported on mordenite zeolite-alumina (HM-Al2O3) compositive support are post-treated by nitric acid leaching at 298 K with different periods (12–48 h). The most dominant effect by acid leaching post-treatment lies in the extraction of aluminum molybdate (Al2(MoO4)3). With this structural transformation, catalysts can sustain 1-butene metathesis reactions with significantly improved stability in propene formation.Figure optionsDownload high-quality image (119 K)Download as PowerPoint slideHighlights
► Acid leaching post-treatment improves the metathesis stability of MoO3/HM-Al2O3.
► Acid leaching extracts aluminum molybdate.
► Aluminum molybdate is detrimental for metathesis stability.
► Removal of aluminum molybdate causes transition in coke species.