Bonde, Jacob Lindner

Chorkendorff, Ib

Horch, Sebastian

Jaramillo, Thomas

Jørgensen, Kristina Pilt

Nielsen, Jane Hvolbæk

Nørskov, Jens Kehlet

Ooi, Bee Lean

Saadi, Souheil

Ulstrup, Jens

Zhang, Jingdong

Online Research Database In Technology

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Downloaded from orbit.dtu.dk on: Dec 17, 2017Electrocatalysis at Nanometer and Sub-Nanometer Scales: Hydrogen Evolution onSupported MoS2 and Mo3S4 ClustersJaramillo, Thomas; Jørgensen, Kristina Pilt; Saadi, Souheil; Bonde, Jacob Lindner; Zhang, Jingdong;Ooi, Bee Lean; Nielsen, Jane Hvolbæk; Horch, Sebastian; Ulstrup, Jens; Nørskov, Jens Kehlet;Chorkendorff, IbPublished in:Meeting Abstracts - Electrochemical SocietyPublication date:2006Document VersionPublisher's PDF, also known as Version of recordLink back to DTU OrbitCitation (APA):Jaramillo, T., Jørgensen, K. P., Saadi, S., Bonde, J. L., Zhang, J., Ooi, B. L., ... Chorkendorff, I. (2006).Electrocatalysis at Nanometer and Sub-Nanometer Scales: Hydrogen Evolution on Supported MoS2 and Mo3S4Clusters. In Meeting Abstracts - Electrochemical Society (pp. Abstract 99). Electrochemical Society,Incorporated.210th ECS Meeting , Abstract #99, copyright ECSElectrocatalysis at nanometer and sub-nanometer scales: Hydrogen evolution on supported MoS2 and Mo3S4 clusters  Thomas F. Jaramillo1, Kristina P. Jørgensen1,  Souheil Saadi2, Jacob Bonde1, Jingdong Zhang3, Bee Lean Ooi3, Jane H. Nielsen1, Sebastian Horch2, Jens Ulstrup3, J.K. Nørskov2, Ib Chorkendorff 1 1 Center for Individual Nanoparticle Functionality, CINF, Nano ·DTU, Department of Physics  2 Center for Atomic-scale Materials Physics, CAMP, Nano·DTU, Department of Physics  3 Nano·DTU, Department of Chemistry   Buildings 312 1, 307 2, and 206 3,  Technical University of Denmark DK-2800 Lyngby, Denmark  Clean, alternative energy carriers will be needed as fossil fuel reserves are depleted. One possible energy carrier under consideration is H2, which can be produced cleanly and renewably if solar or wind energy is coupled to water electrolysis.  Unfortunately, the hydrogen evolution reaction (HER) is catalyzed most effectively by Pt group metals1 – materials that are expensive and scarce. New materials are needed if this scheme is to ever become viable.    Having studied different metal surfaces and enzymes that catalyze hydrogen evolution, we have found a necessary criterion, a “descriptor”, for high catalytic activity – the binding energy (Gibbs free energy) of atomic hydrogen adsorption must be close to zero.1,2 Not surprisingly, the nitrogenase and hydrogenase enzymes – both of which evolve H2 in nature – satisfy this requirement. In an effort to develop solid-state analogues of the enzymatic active sites, theoretical calculations have guided us to MoS2 nanoparticles and Mo3S4 complexes, which were subsequently synthesized and investigated for hydrogen evolution.  Having already confirmed the catalytic activity of MoS2 nanoparticles for hydrogen evolution2, more recently we have aimed to identify relationships between structure and catalytic activity within the MoS2 nanoparticles. In our approach, we combine ultra high vacuum techniques with electrochemical measurements under ambient conditions. MoS2 nanoparticles were first synthesized on Au(111) in ultra-high vacuum, where scanning tunnelling microscopy (STM) was used to investigate their structure, morphology, and surface coverage (Fig. 1). Surface spectroscopy was also employed for chemical characterization. These UHV-prepared samples were then transferred to an electrochemical cell where catalytic activity for hydrogen evolution was measured. By varying particle size and coverage within the sample set, our measurements have established – for the first time – a clear relationship between the structure and catalytic activity of MoS2 nanoparticles.  Bearing in mind the active edge state in MoS2 nanoparticles2, we have looked to other solid-state systems which also mimic the active site within nitrogenase and/or hydrogenase. One candidate material is an aquo, tri-nuclear molybdenum complex, [Mo3S4]4+, which we have synthesized following the procedure in reference 3 (see Fig. 2). Our theoretical model predicts these complexes to be active for hydrogen evolution, and to investigate them experimentally we have deposited them as individual, separate entities onto an inert HOPG substrate. We subsequently characterized these catalysts using STM, surface spectroscopy, and electrochemical methods. The supported Mo3S4 complexes demonstrated excellent catalytic activity for hydrogen evolution, just below that of the Pt-group metals, per active site.        Fig. 1. STM images (width 7 nm and 150 nm) of MoS2 nanoparticles on Au(111).        0.5 nm   Fig. 2. DFT-calculated structure of the protonated [Mo3S4]4+ complex in aq. HCl.    References  1 J.K. Nørskov, T. Bligaard, A. Logadottir, J.R. Kitchin, J.G. Chen, S. Pandelov, U. Stimming, J. Electrochem. Soc. 152, J23 (2005).  2 B. Hinnemann, P.G. Moses, J.Bonde, K.P. Jørgensen, J.H. Nielsen, S. Horch, I. Chorkendorff, J.K. Nørskov, J. Am. Chem. Soc., 127, 5308 (2005).  3 H. Akashi, T. Shibahara, and H. Kuroya, Polyhedron, 9, 1671 (1990). 

Electrocatalysis at Nanometer and Sub-Nanometer Scales: Hydrogen Evolution on Supported MoS2 and Mo3S4 Clusters

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Electrocatalysis at Nanometer and Sub-Nanometer Scales: Hydrogen Evolution on Supported MoS2 and Mo3S4 Clusters

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