Palladium and Proton Knight Shift in Palladium Hydride

Abstract

AbstractThe nuclear magnetic resonance of 105Pd has been observed in α‐PdHn for the first time. The resonant field was measured at 75°C as a function of hydrogen pressure p within the entire α phase region. A linear relationship between Knight shift and hydrogen concentration has been established by comparison with the p(n) absorption isotherm at 75°C. Moreover, it has been found that the 105Pd Knight shift K and the susceptibility x of α‐PdHn are linearly related. From the K — X dependence a value of ‐(1.80 ± 014)% for the Knight shift in pure palladium metal at 75 °C and a value of ‐(1.49 ± 015)% for PdH0.025 at 75 °C could be determined. This may be attributed to the decreasing 4d spin susceptibility within the α phase.The proton Knight shift in α‐PdHn was also studied at 75°C. Similarly to the 105Pd Knight shift the 1H Knight shift in α‐PdHn depends linearly on hydrogen concentration and susceptibility. Knight shifts between ‐(93 ± 8) ppm for PdH0.014 and ‐(50 ± 5) ppm for PdH0.035 relative to the bare proton have been obtained.