A versatile chemical method for the formation of macroporous transition metal alloys from cyanometalate coordination polymers

A Strategy for Fabricating Porous PdNi@Pt Core-shell Nanostructures and Their Enhanced Activity and Durability for the Methanol Electrooxidation

“…Cyanogel, a coordinate inorganic polymer, is a special class of 3D double-metal cyanide, which can be facily achieved by mixing tetrachlorometalates ([RCl 4 ] 2− , R = Sn, Pd, Pt) and cyanometalates ([M(CN) n ] 2−/3− , (n = 4, 6; M = Pd, Pt, Fe, Co, Ni, Ru) aqueous solutions (equation (1))27282930313233. After mixing K 2 PdCl 4 and K 2 Ni(CN) 4 aqueous solutions at room temperature for 10 min, the orange jelly-like K 2 PdCl 4 /K 2 Ni(CN) 4 cyanogel generates slowly (Figure 1A).…”

Low-density nanoporous iron foams synthesized by sol-gel autocombustion

“…Several transition metal porous foams have been obtained by heating the cyanogel under an inert atmosphere. However, as mentioned in the references, there are several disadvantages in their synthesis metrology: firstly, the by-products in their thermal processing contain very toxic hydrogen cyanide and cyanogen; secondly, the metal complexes with energetic ligand bistetrazolamine used in the process are expensive and complex to be synthesized; and thirdly, elemental analysis confirmed that the Fe foams contain only approximately 50% Fe, and the iron foams are not perceptibly magnetic prior to heat treatment under a flow of Ar or H 2 gas [ 23 , 25 ]. In this communication, we demonstrate a method, which is extended from the sol-gel autocombustion route [ 26 ], for the synthesis of nanoporous iron foams.…”

Stabilizing cyanosols: amorphous cyanide bridged transition metal polymer nanoparticles

“…The terminal cyanide stretch of the nanoparticles is shifted from the terminal cyanide stretch in the bulk 1 : 1 cyanogel (2145 cm À1 ) by 11 cm À1 . Given that the frequency of the terminal cyanide stretch is sensitive to the identity of the supporting cation in both cyanogels and monomeric cyanide complexes, 23,29 the shift in the frequency of the terminal cyanide supports the exchange of counter-ions from the alkali cation found in the native gel to CTA + . SEM-EDX line scans, performed with a 2.1 nm spot size, showed the presence of both Pd and Co in the nanoparticle sample.…”

“…19 In the present study, the thermal decomposition of the nanoparticles is investigated since bulk cyanogel polymers are known precursors to transition metal alloys due to the ability of bridging cyanide ligands to act as a reducing agent at relatively low processing temperatures. 12,[20][21][22][23] Sol-gel processing of stabilized cyanosol particles was found to provide a new route to support-free metal alloy nanoparticles.…”