2016 年 51 巻 1 号 p. 7-11
In the Nuclear Science Research Institute, Japan Atomic Energy Agency (JAEA), in order to oxidize 14C, which exists in various chemical forms in exhaust, into 14CO2, a copper oxide (CuO) catalyst is introduced after heating to 600℃. Our goal was to establish a safer 14C monitoring system by lowering the heating temperature required for the catalyst; therefore, we developed a new hydrophobic palladium/silicon dioxide (Pd/SiO2) catalyst that makes the carrier's surface hydrophobic. In these experiments, catalysts CuO, platinum/aluminum oxide (Pt/Al2O3), palladium/zirconium dioxide (Pd/ZrO2), hydrophobic Pd/SiO2, and hydrophilic Pd/SiO2 were ventilated with standard methane gas, and we compared the oxidation efficiency of each catalyst at different temperatures. As a result, we determined that the hydrophobic Pd/SiO2 catalyst had the best oxidation efficiency. By substituting the currently used CuO catalyst with the hydrophobic Pd/SiO2 catalyst, we will be able to lower the working temperature from 600℃ to 300℃ and improve the safety of the monitoring process.
