In organic chemistry, Lewis acid catalysis is the use of metal-based Lewis acids as catalysts for organic reactions. The acids act as an electron pair acceptor to increase the reactivity of a substrate.

These two reactions that take place on the acid sites of catalysts, along with the formation of carbonium ions by protonation of hydrocarbons on Bronsted sites, function as the initiation steps in the ionic chain reactions that lead to the products obtained from catalytic cracking.

Jan 10, 2025 · Results show the synergistic effect between the dual Lewis acid sites of Fe 3+ and Zr 4+ on this Lewis acid catalysis, in which Fe 3+ is prone to activate epoxides while Zr 4+ prefers to react with CO 2. The corresponding reaction mechanism was proposed based on …

Oct 9, 2002 · Reactions of Thianthrene and 10-Phenylphenothiazine with the Lewis Acids─Titanium Tetrachloride, Titanium Tetrabromide, Tin(IV) Tetrachloride, or Antimony(V) Pentachloride: The Competition between Coordination and Oxidation.

In this Highlight, we review the recent development in the design and synthesis of MOFs with Lewis acidity, the characterization techniques of Lewis acid sites, and their applications in heterogeneous catalysis.

Sep 21, 2020 · We propose how the usage of different characterization techniques can enable the closure of knowledge gaps concerning the strength, multiplicity, localization and structure of catalytically...

Oct 2, 2024 · Dehydroxylation affects the structure of Y sites by reducing their vicinal silanol sites. This conversion of Lewis acidic Y sites into nonacidic sites is the primary factor behind the change in acid site quantity and catalytic activity on Y-BEA.

As Lewis acids, they function in a role similar to general acids, stabilizing negative charge in the enzyme active site. This chapter will focus on Lewis acid catalysis in reactions that employ water as a nucleophile.

Jul 15, 2017 · In this work, a literature overview regarding synthesis of Sn-containing silica materials is given, as well as a synopsis of the characterization tools which can be used to unravel the structure of the catalytic active site.

PCH450 showed the best co-catalytic activity for toluene and CO due to its highest Brønsted/Lewis acid value (0.211) and abundant O v. At a 90% conversion rate (T90), the conversion temperature of toluene in mixed pollutants is advanced by 15 °C and that of CO is delayed by 28 °C.