One‐Pot Synthesis of Zeolitic Strong Solid Bases: A Family of Alkaline‐Earth Metal‐Containing Silicalite‐1. Issue 43 (2nd September 2015)

• Record Type: Journal Article
• Authors: Zhou, Yu; Jin, Yanhua; Wang, Meng; Zhang, Wei; Xie, Jingyan; Gu, Jing; Wen, Haimeng; Wang, Jun; Peng, Luming
• Is Part Of: Chemistry. Volume 21:Issue 43(2015)
• Page Start: 15412
• Page End: 15420
• Publication Date: 2015-09-02
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201501894
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Fabricating stable strong basic sites in well‐preserved crystallized zeolitic frameworks still remains a difficult issue. Here, we reported a family of MFI‐type metallosilicate zeolites, AeS‐1 (Ae: alkaline‐earth metal ions of Mg, Ca, Sr or Ba; S‐1: silicalite‐1) through a direct one‐pot hydrothermal method involving the acidic co‐hydrolysis/condensation of the silica precursor with the Ae salts. Step‐by‐step full characterizations were designed and conducted for in‐depth discussion of the Ae status in AeS‐1. Strong basicity (<italic>H</italic>_≈22.5–26.5) was detected in AeS‐1. The basicity was further confirmed by CO₂ sorption measurements, ¹³C NMR spectra of chloroform‐adsorbed samples, and ¹H→¹³C and ¹H→²⁹Si cross‐polarization magic‐angle spinning NMR spectra of ethyl cyanoacetate‐adsorbed samples. The results of Knoevenagel condensations demonstrated the excellent solid base catalysis of AeS‐1, which showed high activity, reusability, and shape‐selectivity, all of which are explained by Ae‐derived zeolitic intracrystalline strong basic sites.</p> </abstract>