MgO/SiO2 prepared by wet-kneading as a catalyst for ethanol conversion to 1,3-butadiene: Prins condensation as the predominant mechanism

Author(s)

Vieira, Jose Lucas ; Destro, Priscila ; Laier, Leticia O. ; Marques, Clelia M. P. ; Gallo, Jean Marcel R. ; Bueno, Jose Maria C.

• Document type: Journal article
• Source: MOLECULAR CATALYSIS; v. 532, p. 9-pg., 2022-10-10.

Abstract

MgO/SiO2 catalysts prepared by wet-kneading with various compositions were applied to directly convert ethanol to 1,3-butadiene. The MgO/SiO2 molar ratio significantly affected the structural, textural, and surface properties of the catalysts, leading to different activities toward ethanol conversion. At low MgO loading (51 mol %), magnesium silicate is formed on the amorphous silica surface, resulting in a higher activity for ethanol dehydration to ethylene. Increasing the MgO loading, crystalline magnesium oxide is formed in addition to the magnesium silicate, producing strong basic sites capable of increasing the ethanol conversion to 1,3-butadiene. Interestingly, for the mixed oxides prepared herein, a linear correlation was found between the forward reaction rate for 1,3-butadiene formation as a function of the reaction rate for acetaldehyde and ethylene. This behavior suggests a predominance of the Prins condensation mechanism. Therefore, the paired arrangement and the strength of the acid-basic conjugate sites of these catalysts must be determinant for the dehydrogenation and dehydration of ethanol and the condensation of the respective intermediates acetaldehyde and ethylene to form 1,3-butadiene. (AU)

• FAPESP's process: 16/02128-2 - Design of new catalytic systems for the biorefinery
• Grantee: Jean Marcel Ribeiro Gallo
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 17/04058-4 - 25th North American Catalysis Society Meeting
• Grantee: Adriano Henrique Braga
• Support Opportunities: Research Grants - Meeting - Abroad
• FAPESP's process: 20/04109-0 - Synthesis of porous acid carbons for the conversion of glucose to HMF
• Grantee: José Lucas Vieira
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 18/01258-5 - Novel chemical catalytic and photocatalytic processes for the direct conversion of methane and CO2 to products
• Grantee: José Maria Correa Bueno
• Support Opportunities: Research Projects - Thematic Grants