Morphological control of inverted MgO-SiO2 composite catalysts for efficient conversion of ethanol to 1,3-butadiene

• Published in: Applied catalysis. A, General General, 2019-05, Vol.577, p.1-9
• Main Authors: Li, Shenxiao, Men, Yong, Wang, Jinguo, Liu, Shuang, Wang, Xuefei, Ji, Fei, Chai, Shanshan, Song, Qiaoling
• Format: Article
• Language: English
• Subjects: 1,3-butadiene; Ammonia; Butadiene; Catalysis; Catalysts; Catalytic activity; Chemical bonds; Chemical synthesis; Conversion; Ethanol; Flower-like; Magnesium oxide; Mg[sbnd]O[sbnd]Si bonds; MgO-SiO2; Moisture content; Morphological control; Morphology; NMR spectroscopy; Organic chemistry; Precursors; Silicon dioxide
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2019.03.007

The effect of MgO precursor morphologies was explored for conversion of ethanol to 1,3-BD. Extensive characterizations demonstrate that the unique layered flower-like architectures may facilitate the formation of interfacial Mg-O-Si species and enhance Lewis basicity on the bridged O in Mg-O-Si bond via the strong interaction between MgO and SiO2 in binary MgO-SiO2 composite catalysts which are favorable for the superior activity. [Display omitted] •Synthesis of three novel MgO-SiO2 composite catalysts by reverse incipient wetness impregnation.•MgO-SiO2 composite catalysts exhibited remarkable morphology-dependent reactivity for Lebedev reaction.•The MgO precursors with different morphologies affect the physicochemical properties of the catalyst surface.•The unique layered structure of the flower-like catalyst is more favorable for 1, 3-butadiene formation.•The MgOSi bond formed plays a crucial role in the formation of 1, 3-butadiene. In this work, three novel MgO-SiO2 composite catalysts with inverted structure have been synthesized via a facile and scalable strategy by means of the incipient wetness impregnation of the silica sol onto MgO precursors with different morphologies, and evaluated for the one-step conversion of ethanol to 1,3-butadiene. The prepared flower-like MgO-SiO2 composite catalysts exhibited highly enhanced catalytic activity than those catalysts synthesized from MgO precursors with nanodisks and nanosheets morphologies. Characterization results based on XRD, FT-IR, UV–vis, BET, CO2-TPD, NH3-TPD, ethanol-TPD, and 29Si MAS NMR revealed that unique layered flower-like architectures may facilitate the formation of interfacial Mg-O-Si chemical bond in binary MgO-SiO2 composite catalysts which are mainly responsible for the superior activity. This study presents a new strategy to design and develop the catalyst for efficient conversion of bio-ethanol to 1,3-butadiene by morphological control of MgO-SiO2 bifunctional catalysts.