Hide/Show Apps

Kinetics of hydrogen adsorption and Desorption on silica-supported Pt, Rh, and Ru catalysts studied by solid state H-1 NMR

Savargaonkar, N
Üner, Deniz
Pruski, M
King, TS
The kinetics of adsorption and desorption of hydrogen on the multifaceted surfaces of silica-supported Pt, Rh, and Ru catalysts were studied by means of solid state H-1 NMR. Experiments with selective inversion of 1H magnetization and the formalism developed by Engelke et al. [J. Chem. Phys. 1994, 101 (9), 7262] were used to extract the adsorption and desorption rate constants and the apparent sticking coefficient. The sticking coefficients of hydrogen measured at 333 K at a surface coverage of 0.4 over 5% Pt/SiO2, 4% Ru/SiO2, and 3% Rh/SiO2 were determined to be 0.014, 0.12, and 0.52, respectively. The corresponding activation energies for desorption were 66, 43, and 79 kJ/mol, respectively.