화학공학소재연구정보센터
Journal of Molecular Catalysis A-Chemical, Vol.158, No.1, 461-465, 2000
Synthesis and study of palladium colloids and related catalysts
Colloidal palladium particles were prepared by reduction with hydrogen of H2PdCl4 in a mixture of H2O, trioctylamine (TOA), and cyclohexane. According to N-14 NMR, Cl-35 NMR and EXAFS data, the reduction of Pd was found to proceed under an auto-catalyzed regime via (HTOA)(2) [PdCl4] complex formation. After complete reduction of Pd(II) (1 mol H-2 consumed per 1 Pd atom), H-2 consumption abruptly changed to 0.7 H-2 mol per 1 Pd atom. Unusually large amounts of H-2 adsorbed per Pd-atom could be due to the formation of palladium hydride by highly dispersed and defected Pd particles. TEM shows that Pd particles in catalysts obtained by metal particles deposition on carbon material Sibunit look like "hedgehogs" with needles 100 Angstrom long and 20-40 Angstrom in diameter.