摘要 |
An inorganic material is described, constituted by at least two elementary spherical particles, each of said spherical particles comprising metallic nanoparticles having at least one band with a wave number in the range 750 to 1050 cm-1 in Raman spectroscopy and containing one or more metals selected from vanadium, niobium, tantalum, molybdenum and tungsten, said metallic nanoparticles being trapped in a mesostructured matrix based on an oxide of an element Y selected from silicon, aluminium, titanium, tungsten, zirconium, gallium, germanium, tin, antimony, lead, vanadium, iron, manganese, hafnium, niobium, tantalum, yttrium, cerium, gadolinium, europium and neodymium. Said matrix has pores with a diameter in the range 1.5 to 50 nm and amorphous walls with a thickness in the range 1 to 30 nm. Said elementary spherical particles have a maximum diameter of 200 microns and said metallic nanoparticles have a maximum dimension strictly less than 1 nm. |