Synergistic role of Brønsted and Lewis acidity in alkali metal-exchanged heteropolyacid catalysts for esterification of acetic acid at room temperature

Design of choline chloride modified USY zeolites for palladium-catalyzed acetylene hydrochlorination

“…Brønsted (B) and both Brønsted and Lewis (B + L) acid sites, respectively. [69][70][71] According to quantitative analysis of the Brønsted/Lewis (B/L) acidity radio for each catalyst at the temperature 160 C was shown in Table S1. † The B/L acidity radio of the fresh Pd@15ChCl@USY catalyst was remarkably higher than that of the fresh Pd@USY catalyst and the pure USY support under the same condition, suggesting that more abundant Brønsted acid sites on the fresh Pd@15ChCl@USY catalyst (as indicated in the NH 3 -TPD results) related to the ChCl additive.…”

Esterification of 1-hexene and acetic acid catalyzed by a modified resin with a Lewis acid

“…It is well known that a homogeneous catalyst faces some inevitable drawbacks such as equipment corrosion, environmental pollution, and complex post-treating processes. [23][24][25] So, the research of heterogeneous catalysts has a broad prospect. At present, the commonly used solid acid catalysts include heteropoly acids, molecular sieves, strong acidic ion exchange resins, etc.26-28 An ion exchange resin catalyst is a functional polymer with the -SO 3 H group, which has unique advantages such as adjustable acidity and cheap and easy recovery.…”

Magnetically Recoverable Catalysts: Catalysis in Synthesis of Polyhydroquinolines

“…Recently, a large number of protocols for the synthesis of this class of N‐ containing heterocyclic molecules have been reported in the literature . Although most of the reported procedures offer obvious advantages, they suffer from some drawbacks i.e. the use of high temperatures, expensive metal precursors, use of expensive or toxic catalysts, the use of a large quantity of volatile and toxic organics, formation of by‐products, product contamination and difficulty in catalyst separation from the reaction media and recycling .…”