Synthesis and Characterization of Supported Co₂P Nanoparticles by Grafting of Molecular Clusters into Mesoporous Silica Matrixes

Abstract

High-quality Co2P nanoparticles have been obtained from diphosphine-substituted molecular cobalt clusters anchored into an inorganic matrix. The synthesis was followed stepwise using a wide panel of analytic techniques. The required functionalization of an ordered mesoporous silica matrix of the type SBA-15 was achieved by covalent attachment of the alkoxysilyl-substituted short-bite diphosphine ligand (Ph2P)2N(CH2)3Si(OMe)3. Anchoring of the cluster [Co4(CO)10(μ-dppa)] (dppa = (Ph2P)2NH) led to an organometallic hybrid mesoporous silica whose thermal treatment led to pure nanocrystalline Co2P particles. Compared with the particles obtained in a silica xerogel, those synthesized into the SAB-15 matrix were the most regular in spatial repartition, size, and shape.

Chemical Routes for Production of Transition‐Metal Phosphides on the Nanoscale: Implications for Advanced Magnetic and Catalytic Materials

“…[41] This was achieved by grafting a bis(phosphane)-terminated ligand to the surface and then using this to anchor a zerovalent cobalt carbonyl cluster. Upon annealing, crystalline Co 2 P nanoparticles (ca.…”

Surface Modification by Deposition and Thermal Decomposition of Transition Metal Cluster Halides

“…This ligand exchange can explain the dierent proportion of Nb / Cl observed in some particles using the SIT-7 and SIT-8 methods 3.6 . Apart from that, the larger methanol outer ligands in the cluster would promote the anchorage of the molecule on the substrate, as reported by Braunstein et al [48,49], which also explains the rather adhesive character of the niobium cluster particles deposited by SIT methods. However, according to chemical mapping analyses, this oxygen comes also from the passivation layer present on the surface of the substrate metals.…”

“…In the second case, which constitutes the main application of cluster compounds in catalysis, heterometallic clusters are used as precursors to obtain bimetallic or trimetallic particles on inert surfaces. Carbonyl clusters are typically used for this purpose since these ligands can be easily eliminated by thermal activation [32,48,49,61,62].…”

GELATION OF N3P3[NH(CH2)3Si(OEt)3]6-n [X]n X = NH(CH2)3Si(OEt)3, NCH3(CH2)3CN AND OC6H4(CH2)CN, n = 0 or 3 at the LIQUID/AIR/INTERFACE

“…For pyrolytic products from (G 2 ) and (G 3 ) a distribution of irregularly shaped dark features was observed as shown in figure 4b and 4c respectively, with also irregular size. Thus, the last of these TEM images are typical of solgel processes of organic /Si(OEt) 3 precursors 10,18,[29][30][31][32][33][34] .…”