Hydrogen absorption performance and mechanism of low-temperature activated Ti-Co-Ce bulk getter

Highlights: • A new type of non-evaporable low-temperature activated Ti-Co-Ce bulk getter was developed. • Ahe hydrogen absorption performance of Ti₈₀Co₁₅Ce₅ is greater than those of Zr-Co-Ce and Zr-V-Fe. • 0.6g Ti₈₀Co₁₅Ce₅ has the highest hydrogen absorption capacity of 143.6 Torr·L or 15.5mg H₂ than Zr-Co-Ce, Zr₃Co and Ti₂Co. • The hydrogen absorption mechanisms of Ti-Co-Ce and Zr-Co-Ce were discussed. -- Abstract: In this paper, a new type of non-evaporable low-temperature activated Ti-Co-Ce bulk getter was prepared. The phase structure, morphology and composition of this getter were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques, respectively. Under the activation condition of 350 °C for 30 min, its hydrogen absorption performance at room temperature was measured through the constant pressure method. The initial hydrogen pumping speed and cumulative absorption capacity within 2 h of Ti₈₀Co₁₅Ce₅ (in the following, all alloy compositions, unless otherwise stated, are composition by weight) getter are 2700 ml/s·g and 4000 Pa·ml/g, respectively, which are more than twice those of Zr_80.8Co_14.2Ce₅ (Zr-Co-Ce) and even greater than those of Zr₇₀V_24.6Fe_5.4 (Zr-V-Fe) under the same preparation, activation and measurement conditions. XRD analysis shows that Ti-Co-Ce getter is mainly composed of (α-Ti) solid solution and Ti₂Co intermetallic compound two phases. (α-Ti) instead of Ti₂Co plays a more important role in hydrogen absorption. The hydrogen absorption performance of Ti-Co (Ti_70.9Co_29.1) getter even without rare earth addition is superior to Zr-Co-Ce, single Ti₂Co or α-Ti phase. Measured by the constant volume method, the saturated hydrogen absorption capacity of 0.6 g Ti₈₀Co₁₅Ce₅ is 143.6 Torr·L or 15.5 mg H₂, higher than that of Zr-Co-Ce, intermetallic compounds Zr₃Co and Ti₂Co.