Uranium-mediated electrocatalytic dihydrogen production from water

Abstract

Depleted uranium is a mildly radioactive waste product that is stockpiled worldwide. The chemical reactivity of uranium complexes is well documented, including the stoichiometric activation of small molecules of biological and industrial interest such as H2O, CO2, CO, or N2 (refs 1 - 11), but catalytic transformations with actinides remain underexplored in comparison to transition-metal catalysis. For reduction of water to H2, complexes of low-valent uranium show the highest potential, but are known to react violently and uncontrollably forming stable bridging oxo or uranyl species. As a result, only a few oxidations of uranium with water have been reported so far; all stoichiometric. Catalytic H2 production, however, requires the reductive recovery of the catalyst via a challenging cleavage of the uranium-bound oxygen-containing ligand. Here we report the electrocatalytic water reduction observed with a trisaryloxide U(III) complex [(((Ad,Me)ArO)3mes)U] (refs 18 and 19)--the first homogeneous uranium catalyst for H2 production from H2O. The catalytic cycle involves rare terminal U(IV)-OH and U(V)=O complexes, which have been isolated, characterized, and proven to be integral parts of the catalytic mechanism. The recognition of uranium compounds as potentially useful catalysts suggests new applications for such light actinides. The development of uranium-based catalysts provides new perspectives on nuclear waste management strategies, by suggesting that mildly radioactive depleted uranium--an abundant waste product of the nuclear power industry--could be a valuable resource.

Highly Sensitive Detection of Ionizing Radiations by a Photoluminescent Uranyl Organic Framework

“…Forinstance,uranium could be utilized as exceptional catalysts for water reduction, [21] photodegradation of organic dyes, [22] oxidative combustion of volatile organic compounds, [23] and activation of small molecules such as N 2 ,CO, and CO 2 ; [24] Theuranium-based heavyfermion compounds exhibit new type of superconductivity distinct from that of the traditional superconductors; [25] Tr ivalent and pentavalent uranium molecular compounds can display single-molecule magnet behavior with noticeably high relaxation barriers. Forinstance,uranium could be utilized as exceptional catalysts for water reduction, [21] photodegradation of organic dyes, [22] oxidative combustion of volatile organic compounds, [23] and activation of small molecules such as N 2 ,CO, and CO 2 ; [24] Theuranium-based heavyfermion compounds exhibit new type of superconductivity distinct from that of the traditional superconductors; [25] Tr ivalent and pentavalent uranium molecular compounds can display single-molecule magnet behavior with noticeably high relaxation barriers.…”

Highly Sensitive Detection of Ionizing Radiations by a Photoluminescent Uranyl Organic Framework

“…Thesubject of uranium-based functional materials besides its nuclear fission properties was substantially underexplored in the past century but is highly desirable given that large inventory of depleted uranium has been piled up from nuclear industry awaiting for disposal. Forinstance,uranium could be utilized as exceptional catalysts for water reduction, [21] photodegradation of organic dyes, [22] oxidative combustion of volatile organic compounds, [23] and activation of small molecules such as N 2 ,CO, and CO 2 ; [24] Theuranium-based heavyfermion compounds exhibit new type of superconductivity distinct from that of the traditional superconductors; [25] Tr ivalent and pentavalent uranium molecular compounds can display single-molecule magnet behavior with noticeably high relaxation barriers. [26] Our forgoing results demonstrate anew application of uranium-based compounds as asuperior, cost-effective,a nd recyclable ionizing radiation dosimeter.…”

Visible‐Light Photocatalysis of C(sp3)‐H Fluorination by the Uranyl Ion: Mechanistic Insights

“…Thef-elementsareofgreatinteresttobothexperimentaland theoretical chemists because of to their application in luminescent materials, [1] molecular functional designations [2] and catalytic activation of otherwise inert covalent bonds. [3] Among these applications,t he feasibility of catalytic CÀH bond transformations have been widely investigated. [4] Owing to the high dissociation energy of the CÀHb ond (90-110 kcal mol À1 ), ap roper mechanism-based catalyst design strategy is the key to achieve the conversion.…”