Lewis Acids: From Conventional Homogeneous to Green Homogeneous and Heterogeneous Catalysis

Sulfated zirconia and its modified versions as promising catalysts for industrial processes

This review article deals with recent progress in the preparation of sulfated zirconia (SZ)-bassed, strong solid-acid catalysts, the characterization of their physicochemical properties and the evaluation of their catalytic performance in various promising applications. Strong emphasis was put on discussion of controversial issues such as the strength of acid sites, the nature of active sites, the reaction mechanism, and the role and state of supported platinum. An important part of this work was devoted to recent catalytic applications.

Sulfated Zirconia-Based Strong Solid-Acid Catalysts: Recent Progress

Brønsted acidity in metal-organic frameworks.

Superacids, defined as acids with a Hammett acidity function H0 ≤ −12, are useful materials, but a need exists for new, designable solid state systems. Here, we report superacidity in a sulfated metal–organic framework (MOF) obtained by treating the microcrystalline form of MOF-808 [MOF-808-P: Zr6O5(OH)3(BTC)2(HCOO)5(H2O)2, BTC = 1,3,5-benzenetricarboxylate] with aqueous sulfuric acid to generate its sulfated analogue, MOF-808-2.5SO4 [Zr6O5(OH)3(BTC)2(SO4)2.5(H2O)2.5]. This material has a Hammett acidity function H0 ≤ −14.5 and is thus identified as a superacid, providing the first evidence for superacidity in MOFs. The superacidity is attributed to the presence of zirconium-bound sulfate groups structurally characterized using single-crystal X-ray diffraction analysis.

/pdf/superacidity-in-sulfated-metal-organic-framework-808-3qiuq3acqg.pdf

Superacidity in sulfated metal-organic framework-808.

https://pure.tue.nl/ws/files/2267329/590935.pdf

V. Adeeva

Papers

Acid Sites in Sulfated and Metal-Promoted Zirconium Dioxide Catalysts