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High Hydrogen Isotope Separation Efficiency: Graphene or Catalyst?

“…The more reliable separation factors after 10 h are summarized in Table . The scheme of NF/Gr-decorated Pt has the highest separation factors of H/D ∼ 7.27 and H/T ∼ 19.50, which are much higher than the reported highest H/T separation factor of 12 in the PEMWE system . However, when compared to the controlled experiment without graphene, the H/D separation efficiency of graphene is rather low, around 1.15.…”

“…The scheme of NF/Gr-decorated Pt has the highest separation factors of H/D ∼ 7.27 and H/T ∼ 19.50, which are much higher than the reported highest H/T separation factor of 12 in the PEMWE system. 56 However, when compared to the controlled experiment without graphene, the H/D separation efficiency of graphene is rather low, around 1.15. The separation efficiency of ink-coated Pt electrode schemes is significantly lower than that of decorated Pt equivalents, and the controlled scheme without graphene, which is a typical Ir/Pt PEMWE structure, is highly consistent with that in the literature.…”

28 Radiochemistry

“…A new method has been described 11 for the separation of tritium from the electrolysis of heavy water using a polymer electrode. The deutron irradiation of natural zinc can be induced to yield isotopes of copper ( 64 Cu and 61 Cu) or gallium ( 66 Ga and 67 Ga) depending on the beam energy; the publication 12 of excitation functions facilitates the optimisation of these reactions.…”

“…The short half-life of carbon-11 (t 1/2 ~20.4 min) imposes special constraints on the radiochemical and indeed ordinary organic chemistry procedures that can be employed in producing labelled molecules for use in nuclear medine; the methods that can be employed have been reviewed 78 as have techniques for the preparation of compounds with a high specific activity. 79 Palladium catalysts have been used in the preparation of a series of [carbonyl- 11 C] labelled amides 80,81 from amines, aryl halides and [ 11 C]carbon monoxide; a variation uses aryl triflates 82 in place of the halide. The labelling of citalopram has also been accompished 83 using [ 11 C]CO. [ 11 C]cyanide is another useful reagent for introducing a carbon-11 label and facilitates the preparation 84 of the labelled amino-acids, phenylalanine and tyrosine.…”

“…The reaction of phosgene with amines has been investigated and a useful route to labelled carbamoyl chlorides 88 from tertiary amines developed. [ 11 C]carbon dioxide can be produced directly from a cyclotron and can either be used in reactions with Grignard reagents for example, to produce [ 11 C]acetate 89 or (after a few more steps and with some micro-wave assistance) [carbonyl- 11 C] amides, 90 or it can be converted into [ 11 C]methyl iodide. This can then be converted to [ 11 C]methyl lithium, a useful reagent in its own right, but which can then react further, with sulfuryl chloride, to produce, 91 in less than half an hour, [ 11 C]mesyl chloride.…”