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In nuclear fusion reactor facilities, the multi-confinement system and the air detritiation system (ADS) are very important to prevent tritium leaking to the environment. A high-performance tritium...

Tritium must be strictly defended in tritium systems because of its permeability and radioactivity. Detritiation devices are required in tritium systems, such as the glove box detritiation system, ...

Strong Metal-Support Interactions (SMSI) are important in Pt supported catalysts for their catalytic performance. SMSI in Pt/CeO 2 , Pt/Ce 0.7 Zr 0.3 O 2 and single atom S-Pt/Ce 0.7 Zr 0.3 O 2 catalysts were studied by in situ Raman spectroscopy and H 2 Temperature-Programmed Reduction. Evidence of SMSI in Pt/CeO 2 and Pt/Ce 0.7 Zr 0.3 O 2 that improve the reduction properties of supports other than H 2 dissociation and spillover is obtained. It was also found that Pt-O and Pt-O-Ce bonding in the said catalysts play an important role in SMSI. The Pt bonding could be ascribed to Pt oxides species (Pt 1 + and Pt 2 + ) with different Pt adsorption sites on CeO 2 surface and which act as intermediates in reduction process. This gives a new insight into the SMSI and explains the observed Pt/CeO 2 reduction characteristics.

The exploration of high-performance and low-cost electrocatalysts for catalyzing both hydrogen and oxygen evolution reaction (HER and OER) at high current density is of vital significance for the commercialization of water splitting. Herein, amorphous NiFe phosphides are electrodeposited on 3D nanoarray-structured nitrogen-doped carbon paper (NCP) for direct use as a hybrid electrode toward overall water splitting. The as-prepared NiFe-P/NCP electrode requires only an overpotential of 0.226 and 0.125 V at 50 mA cm–2 for OER and HER, respectively. In addition, NiFe-P/NCP electrodes are further measured as a catalytic cathode and anode couple (NiFe-P/NCP||NiFe-P/NCP) for overall water splitting, exhibiting a low cell voltage of 1.547 to reach 10 mA cm–2 as well as a long-term durability. Our work reveals the significance of introducing well-designed substrate and bimetallic active species for enhanced electrochemical performance towards overall water splitting.

An ideal carbon support, nanoarray-structured nitrogen-doped graphite foil (NNGF), is facilely prepared via a nitrogen plasma procedure of commercial graphite foil (GFL). After plasma treatment, NNGF owns both the bulk layer of graphite inherited from GFL and surface layer of nanoarray-structured defect-rich N doped carbon. Nanometer-sized NiFe layered double hydroxides (NiFe LDH), as an example, are electrodeposited onto NNGF for direct utilization as an OER electrode. Due to the remained graphite layer, the composite electrode is highly conductive; owing to the strong interaction between N dopants and LDH sheets, the charge transfer is dramatically enhanced; meanwhile the diffusion of liquid reactants and gas products during electrocatalysis is also facilitated by the nanoarray structure. As expected, this hybrid NiFe LDH/NNGF electrode exhibits a low overpotential of 0.191 V at 10 mA cm−2. Such nanoarray-structured carbon material is promising to be a universal support for other active species (e.g. NiCo LDH).

Tritium is indispensable to the fusion reactor engineering, and it must be seriously defended because of its radioactivity and permeability. The method of catalytic oxidation and absorption is the most widely used process for tritium cleanup so far, in which detritiation catalyst is of great importance. The poor stability caused by the agglomeration of noble metal limits the life of detritiation catalysts. Here, Anti–Ostwald Ripening is used to prepare single-atom detritiation catalysts S-Pt/Ce0.7Zr0.3O2 for tritium (HT, DT and T2) oxidation. Single-atom dispersed Pt ensures the catalytic activity and decreased the economic cost. The strong metal-support interaction (SMSI) keeps Pt from aggregating, thus increases the working life of catalyst. And Pd based catalyst supported by a cation ordered κ-Ce2Zr2O8 is prepared for tritiated methane (CH4-xTx) oxidation. Tritiated methane is mostly oxidized by Pd/κ-Ce2Zr2O8 at about 450 °C, which is at least 50 °C lower than normal catalysts (such as Pd/Al2O3).

The method of catalytic oxidation and adsorption is widely used for atmosphere detritiation. But traditional particle catalyst has large gas resistance, which limited the space velocity for detritiation. Honeycomb catalyst can enormously increase the gas handling capacity due to its low pressure drop and high dispersity of active ingredients, but has not been used in detritiation so far. A coating of alumina was deposited on the honeycomb substrate of cordierite using ultrasonic technology. By the method of excessive impregnating, noble metal (Pt or Pd) supported catalysts were prepared. The catalysts were characterized by X-ray diffraction (XRD), N2-adsorption/desorption (Brunauer–Emmet–Teller – BET method), scanning electron microscope (SEM) and laser particles sizer. The result shows that the alumina coatings are well distributed, well knitted and the specific surface area of honeycomb catalyst rises to about 20 m2/g. Catalytic activities were evaluated by H2 conversion rate in gas mixture (with different H2 concentration and various flow rates). The results indicated that all catalysts exhibited excellent catalytic performance for H2 oxidation; the conversions of hydrogen were 100% at room temperature when the gas space velocity was up to 6 × 105 h−1.

Detritiation devices are required in tritium system because of its radioactivity. The method of catalytic oxidation and adsorption is widely used for atmosphere detritiation, but cannot be used in glove box detritiation because of the oxygen-lean atmosphere. A Ce-based oxide-loaded honeycomb catalyst is prepared as a multifunctional detritiation catalyst. The properties of Ce-based support and catalyst are characterized by X-ray diffraction (XRD), N2 adsorption/desorption (Brunauer–Emmet–Teller BET method), and H2 temperature-programmed reduction (H2-TPR), and the catalytic performance is tested under both oxygen-rich and oxygen-lean atmospheres. The Pt/Ce0.7Zr0.3O2 honeycomb catalyst will oxidize hydrogen isotope at room temperature with high space velocity when oxygen is sufficient. When oxygen is deficient, H2 is also fully oxidized by the catalyst at 250 °C, with the oxygen supply from the support reducing.