Synthesis and characterization of copper and aluminum salts of H3PMo12O40 for their use as catalysts in the eco-friendly synthesis of chromanes

Novel Oxidative Desulfurization of a Model Fuel with H2O2 Catalyzed by AlPMo12O40 under Phase Transfer Catalyst-Free Conditions

“…Heteropoly compounds are widely applied as catalysts due to their varied composition and physical-chemical features. Moreover, heteropolyacid compounds are easily synthesized and exhibit the possibility for introducing elements into their structures that are necessary to acquire the desired properties [18]. However, data on the use of heteropolyacid salts in ODS reactions is still scarce.…”

“…In general, polyoxometalate synthesis routes are linear, and the reactions of formation of their salts occur with high yields [18,19]. Herein, the synthesis of both AlPW 12 O 40 and AlPMo 12 O 40 catalysts were directly performed, with yields exceeding ca.…”

Calcium Salts of Tungstophoric Acid Supported on Silica as Novel Catalysts for Tetrahydrofuran Polymerization

“…IR characteristic bands of the special Keggin anion structure were 810 cm - [17]. The oxygen atoms in the anion [PW 12 O 40 ] 3-are divided into four types according to their positions: oxygen bridging W and the heteroatom (a), oxygen at corners (b) and edges (c) are assigned to WO 6 , and the terminal oxygen (d) [27]. All these characteristic bands could be observed on the spectra of bulk H 3 PW 12 O 40 and its calcium salts supported on SiO 2 .…”

“…For the potentiometric titration results, it is proposed that the maximum acid strength of sample's acid sites is revealed by the initial electrode potential (Ei) in curves, and the value (meq n-butylamine/g catalyst) where the inflexion point of curve reached indicates the total number of acid sites of catalyst [13]. The acid strength of acid sites could be classified into the following scale [27]: Ei [ 100 mV (very strong sites), 0 \ Ei \ 100 mV (strong sites), -100 mV \ Ei \ 0 (weak sites) and Ei \ -100 mV (very weak sites).…”

“…Besides the alkaline metal salts and amine salt, the third group metal and transition metal are also implemented as partial neutralization cations of heteropolyacid in catalytic reactions. Mansilla et al [27] prepared aluminum and copper salts of molybdophosphoric acid, which had high catalytic performances and presented stable in reaction solution in the synthesis of chromanes. Tipnis et al [28] synthesized the Al and Fe salt of H 3 PW 12 O 40 supported on inorganic carriers silica, H-ZSM-5, and K10, and among all catalysts the FePW/K10 was found to be recyclable three times without any loss in activity and selectivity in the benzylation of benzene using benzyl chloride.…”