The KKH Research Group

Welcome to our webpage, where you can meet current/past members and find out about our research interests.

The research projects pursued by our group are (mainly) in the field of homogeneous catalysis, at the interface of organic and inorganic chemistry. We are particularly interested in developing selective catalysts for C‑C or C‑X bond formations for organic synthesis. We are working closely with Chemical Engineering colleagues to enhance/understand catalytic processes by the application of continuous flow technology.

Mailing address:

Department of Chemistry

Imperial College London

Exhibition Road, South Kensington

London SW7 2AZ, United Kingdom

Phone: +44-(0)20-75941142

E-mail: mimi.hii@imperial.ac.uk

Who we are:

Vacancies:

 

 

If you wish to explore funding opportunities, please contact Dr. Mimi Hii.

 

We are grateful to the following organisations for their support:

DSM logoGSK logoPfizer logoJason's thesis submission partyRSC logoPPG logo

Recent Publications:

A colorimetric method for rapid and selective quantification of peroxodisulfate, peroxomonosulfate and hydrogen peroxide

B. J. Deadman, K. Hellgardt and K. K. Hii

Abstract: Redox colorimetric tests have been devised for the rapid analysis of the individual components of aqueous mixtures of peroxodisulfate, peroxomonosulfate and hydrogen peroxide; providing a convenient and selective method for the determination of these industrially relevant oxidants, which are known to inter-convert in solution. DOI: 10.1039/C7RE00050B (open access). 

Solvent–dependent nuclearity, geometry and catalytic activity of [(SPhos)Pd(Ph)Cl]2

J. B. Brazier, M. A. Newton, E. M. Barreiro, L. A. Adrio, L. Naya, and K. K. Hii, Dalton Trans. 2017, 46, 7223–7231

Abstract: The nuclearity and structures of the palladium complex [(SPhos)Pd(Ph]Cl]2 in the solid and solution states are revisited, using a combination of Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy, NMR spectroscopy, mass spectrometry, DFT calculations and trapping experiments. The complex was tested for its catalytic activity in the coupling reaction between chlorobenzene and n-hexylamine, where different deactivation behaviour were observed in toluene, 1,4-dioxane and DMF. DOI: 10.1039/c7dt01019b (open access)

Spatial, temporal and quantitative assessment of catalyst leaching in continuous flow

E. M. Barreiro, Z. Hao, L. A. Adrio, K. Hellgardt, and K. K. Hii, Catalysis Today, 2017, in press.

Abstract: A tandem flow-reactor system has been developed, which allowed us to distinguish between surface-catalyzed reactions from those occurring in solution by comparing %conversion at the exit of each reactor (S1, S2) corresponding to predominance of heterogeneous/homogeneous reactions (spatial) and two different residence times (temporal). A multiscale model is subsequently established to quantify the two types of reaction rate and simulate the catalyst leaching from a cross-coupling catalyst, PdEncatTM 30; including: (1) a multi-particle sizes model for catalyst scale; and (2) a dispersion model for reactor scale. The results show that catalyst leaching occurs via more than one process, and that the homogeneous Pd-catalyst (leached from the immobilized catalyst and dissolved in the flow) dominates the reaction and possesses a much higher activity than the heterogeneous (immobilized) Pd-catalyst. Additionally, the change of leached Pd stream inside reactors can be predicted along with the axial direction and the reaction time through the reactor-scale dispersion model. DOI: 10.1016/j.cattod.2017.10.013 (open access).

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