Abstract. Uniform particles of Ni3Ge intermetallic compound (IMC) were prepared inside the pores of MCM-41 mesoporous silica with various mesopore diameters. XRD and TEM revealed that Ni–Ge/MCM-41 thus prepared contained mainly fine metallic particles smaller than the pore size. IR spectra of adsorbed CO suggest the formation of a Ni–Ge IMC, probably Ni3Ge, and the electron transfer fro…