An efficient process to synthesize solketal from glycerol over tin (II) silicotungstate catalyst

Thermodynamic Assessment of Chemical Equilibrium for the Synthesis of Solketal in the Liquid Phase

“…For example, Da Silva et al employed an SnF 2 catalyst at 298 K, obtaining a glycerol conversion of 90 % with A/G = 8. Employing a tin(II) silicotungstate catalyst under the same conditions, they reached a glycerol conversion of 85 % (this work: 91 %) 18, 19. Rahaman et al obtained a glycerol conversion of 89 % at 303 K and A/G = 12, employing an HY zeolite (this work: 92.5 %) 1.…”

How the Cobalt Position in the Keggin Anion Impacts the Activity of Tungstate Catalysts in the Furfural Acetalization with Alkyl Alcohols

“…Due to their structural versatility, various modifications on the Keggin anion have improved their catalytic activity. These are the main changes performed: (i) to convert HPAs to salts after exchange their protons by metal or organic cations, resulting in catalysts highly active in esterification, etherification, acetalization, and hydrolysis reactions; [21–29] (ii) to transform the Keggin HPAs to lacunar salts, removing one MO unit (M=W or Mo), leading to the highly active catalysts in oxidation reactions with hydrogen peroxide of olefins, alcohols, and aldehydes; [30–35] and (iii) to doping lacunar Keggin anion with a transition metal cation, resulting in efficient catalysts in oxidative transformations [36–41] …”

“…[18][19][20] Due to their structural versatility, various modifications on the Keggin anion have improved their catalytic activity. These are the main changes performed: (i) to convert HPAs to salts after exchange their protons by metal or organic cations, resulting in catalysts highly active in esterification, etherification, acetalization, and hydrolysis reactions; [21][22][23][24][25][26][27][28][29] (ii) to transform the Keggin HPAs to lacunar salts, removing one MO unit (M=W or Mo), leading to the highly active catalysts in oxidation reactions with hydrogen peroxide of olefins, alcohols, and aldehydes; [30][31][32][33][34][35] and (iii) to doping lacunar Keggin anion with a transition metal cation, resulting in efficient catalysts in oxidative transformations. [36][37][38][39][40][41] An important aspect is that the size of cation can modulate the solubility of these salts (i. e., lacunar, metal-doped); while salts containing highly charged counterions such as small-sized metal cations are soluble in a polar solvent, those having large radium cations are almost insoluble.…”

MOF-derived zirconia-supported Keggin heteropoly acid nanoporous hybrids as a reusable catalyst for methyl oleate production

“…15 Contrarily, heteropoly acids have advantages such as strong Brønsted acidity and special Keggin-type structural properties for acid-catalyzed reactions. 19,20 However, unsupported heteropoly acids have high solubility in polar media and low surface area, which limit their industrial applications. [21][22][23] Therefore, the design of heteropoly acids encapsulation into the excellent and stable porous supported for biodiesel production is still a great challenge.…”