Lacunar Keggin Heteropolyacid Salts: Soluble, Solid and Solid-Supported Catalysts

Cesium‐Exchanged Lacunar Keggin Heteropolyacid Salts: Efficient Solid Catalysts for the Green Oxidation of Terpenic Alcohols with Hydrogen Peroxide

“…The region of 1200 to 400 cm −1 of FT–IR spectra shows the typical absorption bands (i. e., fingerprint region) of the bonds present in the lacunar Keggin anion . Moreover, when Phosphorus is the central element, FT–IR spectrum allow to assure that saturated heteropolyanion (i. e., PW 12 O 40 3− or PMo 12 O 40 3− ) was converted to lacunar anion (i. e., PW 11 O 40 7− or PMo 11 O 40 7− ) …”

“…[43] Moreover, when Phosphorus is the central element, FT-IR spectrum allow to assure that saturated heteropolyanion (i. e., PW 12 O 40 7À ). [33,42] Infrared spectra of phosphotungstate anion displayed absorption bands at followings wavenumbers: 1081, 982, 920, 888 and 790 cm À 1 . These data agree with literature and were assigned to the stretching of PÀ Oa, WÀ Od, WÀ Ob-W and WÀ Oc-W bonds, respectively.…”

“…This inexpensive, atom efficient and nonflammable oxidant, results only in water as by‐product . Therefore, the creation of a vacancy in the Keggin heteropolyanion, and the protons exchange by larger radium metal cations, led the lacunar Keggin HPA salts to be suitable catalysts for oxidation reactions with hydrogen peroxide in heterogeneous catalysis conditions …”

“…[32] Therefore, the creation of a vacancy in the Keggin heteropolyanion, and the protons exchange by larger radium metal cations, led the lacunar Keggin HPA salts to be suitable catalysts for oxidation reactions with hydrogen peroxide in heterogeneous catalysis conditions. [33] In this work, we have investigated the catalytic activity of solid Keggin HPAs (i. e., cesium-exchanged lacunar salts) in oxidation reactions of terpenic alcohols with hydrogen peroxide. Three cesium HPA salts were easily synthesized starting from their precursor salts.…”

Highly Crystalline Mesoporous Phosphotungstic Acid: A High‐Performance Electrode Material for Energy‐Storage Applications

“…HF is not only highly toxic, but it can also react with cell active components, such as binders and various additives in the cell, and passive components, such as the solid electrolyte interphase (SEI) layer on the anode, resulting in a serious threat to the lifetime of LIBs . The low specific surface area of bulk PTA is also one of the drawbacks of this material, which limits its application in LIBs . Several strategies have been adopted to overcome these limitations, including anchoring of the PTA onto mesoporous silica as a support .…”