Investigation of the Effects of Parameters on the Properties an‎d Microstructure of CuO ZnO Al2O3 Catalysts Used in the Hydrogenation of Aldehydes

10/22/2026 12:00:00 AM

Aldehyde hydrogenation is an established approach to producing some widely used an‎d deman‎ded alcohols. Over the years, CuO ZnO Al2O3 catalyst have emerged to be the materials of choice to catalyze hydrogenation reaction. The co precipitation synthesis of these catalysts has always been a recurring subject of study, however, still remains the need for investigations of more depth an‎d extension. This study deals with the effects of aging time an‎d precipitation method on the physical an‎d textural properties of a certain class an‎d composition of CuO ZnO Al2O3 catalysts. To study aging time, a set of samples were conventionally co precipitated aged for three different periods of zero, two, an‎d four hours. To study precipitation method, a sample was co precipitated conventionally an‎d a set of samples precipitated sequentially—in which a Cu Zn based precipitate was co precipitated onto a formerly precipitated Al based precipitate. Along with a comparison of the conventional an‎d sequential methods, the effect of the precipitation duration of the initial aluminous precipitate (zero, 15, 30, an‎d 60 minutes) in the sequential method was also investigated. The characterization of the samples was carried out using x ray diffraction (XRD), atomic absorption spectroscopy (AAS), Brunauer Emmet Teller (BET) surface area an‎d porosity analysis, field emission scanning electron microscopy (FE SEM), temperature programmed reduction (TPR), an‎d reactive frontal chromatography (RFC). The results indicate that an aging duration of 2 hours yields a maximum metallic copper surface area of 112 m2/gCu. I was also found that aging durations longer than 2 hour sensibly deteriorates the BET surface area of the catalyst. Regarding the precipitation method, the results suggest that the use of sequential precipitation method rather than conventional co precipitation leads to both higher metallic copper an‎d BET surface area values. The highest metallic copper surface area was achieved in the sample whose initial aluminous precipitate was precipitated during a period of 30 minutes. The presence of an optimum values for this parameter was attributed to an interplay between the Cu Zn interdispersion an‎d crystallite size of the malachite phase; such that the highest Cu0 surface area was achieved in sample exhibiting the highest Cu/Zn interdispersion an‎d the lowest malachite crystallite size.

كاتاليزگر هيدروژناسيون , سامانۀ CuO-ZnO-Al2O3 , هم‌رسوبي , پيرسازي , رسوب‌دهي ترتيبي

Hydrogenation Catalyst , CuO-ZnO-Al2O3 System , Co-precipitation , AgingSequential Precipitation

Mohammad Hossein Ghayour Anarjan

Hossein Sarpoolaky - Hajar Ghanbari