title: Chemical activity of palladium clusters: Sorption of hydrogen.
abstract: Samples of Pd/SiO2 with average cluster size of palladium (d(Pd)) ranging from 1 to 10 nm were prepared by different methods, such as incipient wetness impregnation (IW), ion exchange (IE), and sol-gel (SG). The dispersion (D(Pd)) for prepared Pd/SiO2 samples varied with the method of preparation and showed a trend of IW < IE < SG. Chemical interaction between the dispersed nanopalladium and hydrogen gas was calorimetrically studied as a function of hydrogen uptake. Measured profiles of interaction energy vary with the d(Pd) of studied samples. The initial heat of hydrogen chemisorption (Q(Hi)) also steeply increases for particles with d(Pd) smaller than 2 nm.
authors.affiliation: Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30013, Republic of China.
authors.forename: Sheng-Yang
authors.initials: SY
authors.lastname: Huang
authors.forename: Chin-Da
authors.initials: CD
authors.lastname: Huang
authors.forename: Boh-Tze
authors.initials: BT
authors.lastname: Chang
authors.forename: Chuin-Tih
authors.initials: CT
authors.lastname: Yeh