Experimental Study on Chemical Behaviors of Non-Metal Impurities in Pb, Pb-Bi and Pb-Li by Temperature Programmed Desorption Mass Spectrometer Analysis

Abstract

The chemical behaviors of non-metal impurities such as O 2 , H 2 , N 2 , H 2 O, CO 2 and CO in lead (Pb) metal, lead-bismuth (Pb-Bi) alloy and lead-lithium (Pb-Li) alloys were experimentally investigated by means of temperature programmed desorption mass spectrometer (TPD-MS) analysis. Desorption of H 2 O and CO 2 from the Pb metal and the Pb-Bi alloy was clearly detected by TPD-MS analysis. However, desorption of H 2 O and CO 2 from the Pb-Li alloys was much less than that from the Pb metal and the Pb-Bi alloy, since these molecules are chemically unstable and react with Li in the Pb-Li alloys. Then, oxygen and hydrogen must be dissolved in Pb-Li alloys as they form the chemical compounds of Li (i.e., Li 2 O, LiOH and LiH). Large desorption of hydrogen from solid Pb-Li alloys by their heating was detected. The possible mechanism for the large desorption of hydrogen from the Pb-Li alloys is based on the decomposition of LiH and Pb-Li-H at high temperature. The chemical behaviors of the non-metal impurities in the Pb-Li alloys was modeled based on the thermodynamic stability. The methodologies for the fabrication of high-purity Pb-Li alloys and the control of the impurity condition are discussed.

Synergized Cu/Pb Core/Shell Electrocatalyst for High-Efficiency CO2 Reduction to C2+ Liquids

“…However, for the CuPb-0.7/C, it appears other desorption peaks at high temperatures (310 and 312 °C) for CO 2 -TPD and CO-TPD, respectively. According to the reported studies and existed results, 41,42 the former peaks can be attributed to the chemical adsorption of CO 2 and CO on Pb shell, respectively, while the high temperature peaks are attributed to the chemical adsorption of CO 2 and CO on Cu/Pb interfaces. This result suggests that the CuPb-0.7/C has strong bonding strength to CO 2 and CO, which is propitious to further reduce them into C 2+ products during CO 2 RR.…”