Ru(iii) -based polyoxometalate tetramers as highly efficient heterogeneous catalysts for alcohol oxidation reactions at room temperature

Abstract

A novel ruthenium-containing polyoxometalate-based organic-inorganic hybrid, K4Na9H7.4[(AsW9O33)4(WO2)4{Ru3.2(C3H3N2)2}]·42H2O (1) has been successfully synthesized by an one-step hydrothermal method under acidic condition, which applied self-assemble strategy between inorganic polyoxometalate based on trivacant...

Controlled Assembly of a Dawson-like Antimoniotungstate-Supported Trefoil-type Trimer with Good Proton Conductivity Performance

“…Polyoxometalates (POMs), regarded as nanomultifunctional and discrete metal–oxygen clusters based on early transition metals (W, Mo, V, Ta, Nb, etc.) in their highest oxidation states, are of great interest owing to their well-defined architectures and broad prospects in numerous applications such as proton conduction, catalysis, medicine, biological science, and material science. − Up to now, a variety of classical structures of POMs have been reported, denoted as Keggin, Dawson, Lindquist, Anderson, and Silverton types, which are frequently employed as inorganic building blocks for further modification of POMs or the construction of novel hybrid materials . In addition, as a valuable subclass of basic building blocks in the field of large POM family, the Dawson-type architectures are attracting the interests of researchers .…”

Cu-containing polyoxometalate-based melamine in the environmental remediation of toxic organic pollutants

“…11 In terms of diverse utilizations, their catalytic performance is the most common and prevalent application. Hence, they are considered as promising and eco-friendly catalysts in many fields involving cycloaddition reactions, 12 ring-opening reactions, 13 olefin hydrocarboxylation reaction, 14 degradation, 15 water splitting, 16 oxidation reactions, 17 reduction reactions, 18 and others. Despite the unique POM properties, their catalytic activities have some limitations, such as low surface area and high solubility in aqueous solutions.…”

Construction of Hexameric Ru-Substitution POMs to Improve Photocatalytic H2 Evolution

“…Polyoxometalates (POMs) are emerging as excellent candidates in the photocatalysis thanks to their well-defined structures, oxygen-rich surfaces, and adjustable light absorption range. − Furthermore, POMs feature a unique structure similar to an electron storage layer, which can be light-driven to achieve a multielectron transfer process between metal and oxygen while maintaining structural stability. − Typical POMs, however, absorb UV light, which limits their use in photocatalysis. , By replacing or inserting one or more transition metal atoms in POMs, changes in their electronic structure occur, thus exhibiting light absorption in the visible region and broadening their application in photocatalysis. , Nevertheless, although many transition metal-based POM (e.g., Mn, Co, Ni, and Cu) H 2 evolution catalysts have been reported, there are still some problems such as low activity and poor stability. − Over the past few years, POMs doped with noble metal atoms gradually became a key research topic in the field of POMs . In particular, ruthenium (Ru) possesses excellent catalytic properties, and its combination with POMs to form Ru-POMs exhibits remarkable photocatalytic activity through intercomponent synergy or charge modulation. − Our group had created a series of Ru-POMs, including dimeric ([(Ru­(OH)) 2 ­O­(W 5 O 18 ) 2 ] 8– ), tetrameric ([As 4 W 40 O 140 ­{Ru 2 (CH 3 COO)} 2 ] 14– , [(AsW 9 O 33 ) 4 ­(WO 2 ) 4 ­{Ru 3.2 (C 3 H 3 N 2 ) 2 }] 20.4– , [{Ru 4 (H 2 O) n }­(WO 2 ) 4 ­(AsW 9 O 33 ) 4 ] 16– , [Ru 4 (H 2 O) 2 (Cl) 2 ­(WO 2 ) 4 ­(AsW 9 O 33 ) 4 ] 18– ), and hexameric ([(RuO 6 )­(AsW 9 O 33 ) 3 ­{(W 6 O 3 )­(H 2 O) 6 }] 2 12– ) in recent years and discovered that they have remarkable catalytic activity for the oxidation of benzylamine, sulfides, alcohol, and aniline. − And yet Ru-POMs remain challenging to synthesize, especially in terms of the separation of larger cluster structures . Therefore, further research will be done on the creation and investigation of giant Ru-POMs as well as exploration of their photocatalytic activities.…”