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Alumina‐Supported Alkali and Alkaline Earth Metal‐Based Catalyst for Selective Decarboxylation of Itaconic Acid to Methacrylic Acid
Author(s) -
Ali Hadi,
Kansal Sushil Kumar,
Saravanamurugan Shunmugavel
Publication year - 2021
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202100572
Subject(s) - chemistry , itaconic acid , methacrylic acid , catalysis , alkaline earth metal , nuclear chemistry , decarboxylation , inorganic chemistry , alkali metal , yield (engineering) , organic chemistry , materials science , polymerization , metallurgy , copolymer , polymer
The present study focuses on selective decarboxylation of itaconic acid (IA) to methacrylic acid (MAA) using alkali and alkaline earth metals (Na, K, Mg and Ca) supported on Al 2 O 3 , prepared by incipient wet impregnation approach. The parent Al 2 O 3 , predominantly composed of the boehmite phase, is entirely transformed to γ‐Al 2 O 3 phase upon impregnating calcium, based on XRD analysis, and this is not the case for other metals employed in this study. FTIR analysis corroborates the complete decomposition of nitrate precursor in the case of calcium than other metals (Na, K and Mg). UV‐Vis analysis using diffused reflectance mode suggests that Ca incorporated on to the Al 2 O 3 matrix. Among the catalysts employed, the highest yield of methacrylic acid (MAA) (46.7 %) is achieved with 5 wt % Ca/Al 2 O 3 at 250 °C, 20 bar N 2 after 3 h. Moreover, 15.1 % of α‐hydroxyisobutyric acid (α‐HIBA), a hydrated product of MAA, is also obtained, and thus, the combined yield of MAA and α‐HIBA is 61.8 %. The selective decarboxylation of IA to MAA/α‐HIBA can be correlated with the number of basic sites present in the 5 wt % Ca/Al 2 O 3 , which possess the highest number of basic sites than other catalysts.