Porträt Dr. Müller, Katharina; FWOG

Photo: André Wirsig

Dr. Katharina Müller

Head Surface Processes
Phone: +49 351 260 2439

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Department of Surface Processes

The why? The how? The what?

The ultimate goal of our research, driven by scientific curiosity, is to gain fundamental and independent knowledge of the (geo)chemistry and environmental fate of long-lived radionuclides (RNs). One prominent and socially important application is the safe disposal of radioactive waste, to aid future generations in the responsibility of dealing with “our” legacy from energy production in nuclear reactors.

For this purpose we provide the radiochemical knowledge, namely structural and mechanistic data of important mobilizing and immobilizing reactions of RNs in solution, at interfaces, and in solids.

Our particular focus is using a variety of established and advanced microscopic and spectroscopic techniques, to accurately describe complex formation reactions and complex structures that govern RN interactions in the geosphere. In addition, we investigate the creation and chemical speciation of activation products in materials from nuclear power plants in the context of their safe decommissioning.

As part of a value chain, the derived structural information forms a sound basis for a reliable thermodynamic description of the investigated systems, which can be integrated in thermodynamic databases. The thermodynamic work is done in close collaboration with the department of Actinide thermodynamics.

Foto: Forschungsfelder der Abteilung Grenzflächenprozesse ©Copyright: Dr. Katharina Müller

Our core competencies

  • Chemistry of long-lived RNs – Expertise in handling RNs, ranging from fission- and activation products to transuranium elements, and access to radiation safety labs.
  • Structural characterization – Expertise in applying and coupling spectroscopic and microscopic as well as diffraction techniques for accessing molecular information.
  • Thermodynamic description of RN complexes – Using macroscopic, spectroscopic, and calorimetric information of reactant-water-surface phenomena as basis for the derivation of surface complexation models and their thermodynamic parameters.

Research fields

  • Coordination chemistry of RNs in aqueous solution and in human artificial biofluids, e.g. RADEKOR project.
  • Molecular characterization of RN reactions at natural and engineered mineral-water interfaces, e.g. REDOX project.
  • Incorporation of actinides and lanthanides in solid phases, e.g. AcE project.
  • Environmental technetium chemistry., e.g. Young Investigator Group TecRad.
  • Development of a method for pre-activity and dose rate calculations of components in the reactor vicinity based on neutron fluence distributions (EMPRADO) 12/2018 –11/2022, BMBF.

Latest Publication

Eu(III) and Cm(III) Complexation by the Aminocarboxylates NTA, EDTA, and EGTA Studied with NMR, TRLFS, and ITC – An Improved Approach to More Robust Thermodynamics

Friedrich, S.; Sieber, C.; Drobot, B.; Tsushima, S.; Barkleit, A.; Schmeide, K.; Stumpf, T.; Kretzschmar, J.

The complex formation of Eu(III) and Cm(III) was studied with tetradentate, hexadentate, and octadentate coordinating ligands of the aminopolycarboxylate family, viz. nitrilotriacetate (NTA³), ethylenediaminetetraacetate (EDTA⁴), and ethylene glycol-bis(2-aminoethyl ether)-N,N,N′,N′-tetraacetate (EGTA⁴), respectively. Based on the complexones’ pKa values obtained from ¹H nuclear magnetic resonance (NMR) spectroscopic pH titration, complex formation constants were determined by means of parallel-factor-analysis-assisted evaluation of Eu(III) and Cm(III) time-resolved laser-induced fluorescence spectroscopy (TRLFS). This was complemented by isothermal titration calorimetry (ITC), providing the enthalpy and entropy of the complex formation. This allowed us to obtain genuine species along with their molecular structures and corresponding reliable thermodynamic data. The three investigated complexones formed 1:1 complexes with both Eu(III) and Cm(III). Besides the established Eu(III)–NTA 1:1 and 1:2 complexes, we observed, for the first time, the existence of a Eu(III)–NTA 2:2 complex as of millimolar metal and ligand concentrations. Demonstrated for thermodynamic studies on Eu(III) and Cm(III) interaction with complexones, the utilized approach is commonly applicable to many other metal–ligand systems, even to high-affinity ligands.

Keywords: Europium; Curium; Metal complex; Spectroscopy; Calorimetry; Stability constant; High-affinity ligand

A list of publications can be found here.

Research groups

Currently running third-party funded projects

  • Interactions of technetium with microorganisms, metabolites and at the mineral-water interface – Radioecological considerations (TecRad) 07/2022 – 06/2027, BMBF
  • Redox reactivity of selenium in environmental geomedia (REDOX) 06/2022 – 05/2025, ANDRA
  • Speciation and transfer of radionuclides in the human organism especially taking into account decorporation agents (RADEKOR) 07/2020 – 12/2023, BMBF.
  • Fundamental investigations of actinide immobilization by incorporation into solid phases relevant for final disposal (AcE) 01/2021 – 12/2023, BMBF.
  • Means for efficient decommissioning of reactor components and concrete shielding: Calculation of the activity inventory and their validation on drilling cores as well as mobility investigations of radionuclides (WERREBA) 07/2019 – 12/2022, BMBF.

An overview of finished projects can be found here.



NameBld./Office+49 351 260Email
Dr. Katharina Müller801/P2482439


NameBld./Office+49 351 260Email
Daniel Butscher801/P3523154
Aline Chlupka801/P2033198
Sebastian Friedrich801/P3523154
Dr. Norbert Jordan801/P2182148
Christa Müller3198
Stephan Weiß801/P3162758

Incorporation in solid phases

NameBld./Office+49 351 260Email
Dr. Nina Maria Huittinen801/P2182148
Dr. Astrid Barkleit801/P2073136
Luiza Braga Ferreira dos Santos801/P2543487

"TecRad" Wechselwirkung von Technetium mit Mikroorganismen, Metaboliten und an Mineral-Wasser-Grenzflächen - Radioökologische Betrachtungen

NameBld./Office+49 351 260Email
Dr. Natalia Mayordomo Herranz801/P2522076
Caroline Bö
Irene Cardaio801/P2542251
Vijay Kumar Saini801/P3523328


Name at HZDR Derzeitigte Institution
Quirina Isabella Roode-Gutzmer Ph.D. student Fraunhofer-Institut für Keramische Technologien und Systeme IKTS
Maximilian Demnitz Ph.D. student,
graduated 2022
Eindhoven University of Technology, Department of Chemical Engineering and Chemistry, Het
Diana Marcela Rodriguez Hernandez Ph.D. student,
graduated 2021
Rotop Pharmaka GmbH
Henry Lösch Ph.D. student,
graduated 2021
Radiation Protection, Analytics & Disposal (VKTA)
Manuel Eibl Ph.D. student,
graduated 2020
Avantgarde Labs GmbH
Susanne Lehmann Ph.D. student,
graduated 2020
Institute for Geosciences at the Friedrich-Schiller-University Jena