Deposition of Ni nanoparticles onto porous supports using supercritical CO ₂ : effect of the precursor and reduction methodology

Abstract

SummaryThe deposition of Ni nanoparticles into porous supports is very important in catalysis. In this paper, we explore the use of supercritical CO 2 (scCO 2 ) as a green solvent to deposit Ni nanoparticles on mesoporous SiO 2 SBA-15 and a carbon xerogel. The good transport properties of scCO 2 allowed the efficient penetration of metal precursors dissolved in scCO 2 within the pores of the support without damaging its structure. O were tried as precursors. Different methodologies were used: impregnation in scCO 2 and reduction in H 2 /N 2 at 400 ºC and low pressure, reactive deposition using H 2 at 200-250 ºC in scCO 2 and reactive deposition using EtOH at 150-200 ºC in scCO 2 . The effect of precursor and methodology on the nickel particle size and the material homogeneity (on the different substrates) was analyzed. This technology offers many opportunities in the preparation of metalnanostructured materials.

Preparation of Pt/Al2O3 and PtPd/Al2O3 catalysts by supercritical deposition and their performance for oxidation of nitric oxide and propene

“…In sequential SCD, the single component SCD procedure is applied twice [17,18]. This technique has been used to prepare a wide range of supported monometallic NPs such as Pt, Pd, Ru, Au, Cu, Ni, and Ag; and bimetallic NPs such as PtPd, PtCu, PtRu, PtAu, and AgAu with numerous supports such as carbon aerogels [16,17,19,23], graphene aerogels [24], carbon nanotubes [25], SiO2 [26][27][28][29][30][31][32][33][34], carbon black [18,35], Al2O3 [13,14,[36][37][38], and TiO2 [35,37]. Supercritical carbon dioxide (scCO2) is commonly used in SCD since it is inexpensive, abundant, non-toxic, non-flammable, environmentally benign, has an easily accessible critical temperature and pressure (Tc = 31.1 o C, Pc = 7.38 MPa), and leaves no residue on the treated medium.…”

Role of supercritical carbon dioxide (scCO2) in fabrication of inorganic-based materials: a green and unique route

“…Then, the rice-like manganese oxide (MnO) nanoparticles were tightly embedded in the SiOC matrix by the Chlorella-based bio-sorption process, providing an effective strategy to prepare high capacity SiOC-based anode materials for efficient Li-ion batteries [ 80 ]. In this vein, several efforts have been dedicated to using the SCD method towards the precipitation of the nanoparticles or films of inorganic architectures like colloidal particles [ 74 ], carbon nanotubes [ 8 ], silica-based matrices [ 81 ], and aerogels or xerogels [ 82 , 83 ]. Various metallic substrates with exceptional properties include nickel (Ni), copper (Cu), platinum (Pt), silver (Ag), palladium (Pd), cobalt (Co), and gold (Au).…”

Designing nanocomposites using supercritical CO2 to insert Ni nanoparticles into the pores of nanopatterned BaTiO3 thin films

“…The same approach was extended to deposit Ni nanoparticles into porous supports. [22][23][24][25][26] The low surface tension, high diffusivity and low viscosities of CO 2 solutions allow to deposit or incorporate metallic nanoparticles into a wide variety of inorganic and organic substrates for microelectronic, optical and catalytic applications.…”