Transformations of butyraldehyde in the presence of catalysts based on large-pore molecular sieves VPI-5 and AlPO4-8

It is found that zeolite-like crystalline aluminophosphates VPI-5, Si-VPI-5, and Mn-VPI-5 as well as those dirived from them, AlPO{in4}-8, SAPO{in4}-8, and MnAPO{in4}-8, are capable of catalyzing aldol condensation and crotonization of butyraldehyde (BA). Pd/AlPO{in4}-8 is catalytically active in hydrocondensation of BA with H{in2} at atmospheric pressure. The activities in BA conversion to 2-ethylhexane-3-ol-1-al increase in the following order: Mn-VPI-5 < Si-VPI-5 < VPI-5. The same order of activities is also found for AlPO{in4}-8, SAPO{in4}-8, and MnAPO{in4}-8. These catalysts are characterized by a lower initial activity in crotonization of BA than M{su+}NaX (CsNaX), but they are much more stable. Pd/AlPO{in4}-8 catalyzes BA conversion to 2-ethylhexanal even in the absence of H{in2} feed to the reaction zone. The influence of catalyst pretreatments and experimental conditions on the catalyst structures and catalytic activities is discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khmicheskaya, No. 12, pp. 2123–2129, December, 1994.