Metal oxide and bimetallic nanoparticles in ionic liquids: synthesis and application in multiphase catalysis

Abstract

Ionic liquids (ILs) are well established as solvents and stabilizing agents for the synthesis of metallic nanoparticles (NPs) in general. The physicochemical properties of ILs and the supramolecular organization in the liquid state are capable of directing the growth of transition metal NPs generated in situ and to subsequently protect and stabilize them. Until now, many different NPs have been successfully synthesized within these media; however, the synthesis of metal oxide and bimetallic alloy or core-shell NPs in ILs is still relatively rare. Herein, we summarize the current state-of-the-art of the synthetic methods for these materials and their application in the broad field of catalysis, including multiphase systems, hydrogenation, dehydrogenation, functionalization, as well as defunctionalization reactions.

Synthesis and Dissolution of Metal Oxides in Ionic Liquids and Deep Eutectic Solvents

“…The present review article summarises the current state of knowledge on metal oxide chemistry in ILs and DESs in order to provide researchers an overview about the synthetic approaches. Several review articles cover some fields in metal oxide chemistry [21][22][23], however, no comprehensive summary about the state of knowledge regarding this topic exists. In the following, the first section is concerned with the synthesis of metal oxides, while the second part introduces the dissolution chemistry of metal oxides in ILs and DESs.…”

Controlled Synthesis of Polyions of Heavy Main-Group Elements in Ionic Liquids

“…Recently, several comprehensive reviews on syntheses of inorganic compounds in ILs have been published by Taubert [52], Feldmann [28], Dehnen [51], Janiak [42,53], Scrosati and Passerini [48], Morris [54], Mudring [55], Prechtl [56], Zhu [57], Dai [58], and Ruck [23,27,59] among others.…”

Bimetallic Nanoparticles in Alternative Solvents for Catalytic Purposes

“…Ionic liquids (ILs) exhibit distinctive physico-chemical properties (low vapor pressure, wide temperature range for the liquid phase, low coordinative properties, thermal and chemical stability, broad electrochemical window); these features permit one to control the assembling, size, and shape of metal nano-systems [65,66]. Although the contributions concerning mono-metallic and metal oxide nanoparticles have received a greater interest by the scientific community [67][68][69], BMNPs in ionic liquids are quickly appearing in the literature, mainly concerning late transition metals [see the following selected contributions [70][71][72][73][74]. Prechtl and Gómez groups have recently reviewed the synthesis of BMNPs in ILs for catalytic purposes [67,75].…”

“…Although the contributions concerning mono-metallic and metal oxide nanoparticles have received a greater interest by the scientific community [67][68][69], BMNPs in ionic liquids are quickly appearing in the literature, mainly concerning late transition metals [see the following selected contributions [70][71][72][73][74]. Prechtl and Gómez groups have recently reviewed the synthesis of BMNPs in ILs for catalytic purposes [67,75]. Hereafter, we describe the works of BMNPs in ionic liquids applied in catalysis, organized according to the two main synthetic methodologies involved in their syntheses: (i) co-decomposition of two metal precursors; and (ii) sequential processes, where the first decomposed metal precursor acts as a seed for the deposition of the second one; chemical and physical strategies have been carried out for both approaches.…”