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19 Feb 12:56

Selective Dinitrogen Conversion to Ammonia Using Water and Visible Light through Plasmon-induced Charge Separation

by Tomoya Oshikiri, Kosei Ueno, Hiroaki Misawa


The generation of ammonia from atmospheric nitrogen and water using sunlight is a preferable approach to obtaining ammonia as an energy carrier and potentially represents a new paradigm for achieving a low-carbon and sustainable-energy society. Herein, we report the selective conversion of dinitrogen into ammonia through plasmon-induced charge separation by using a strontium titanate (SrTiO3) photoelectrode loaded with gold nanoparticles (Au-NPs) and a zirconium/zirconium oxide (Zr/ZrOx) thin film. We observed the simultaneous stoichiometric production of ammonia and oxygen from nitrogen and water under visible-light irradiation.

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NH3 sees the light of day: A highly selective and visible-light-responsive plasmonic NH3 synthesis device containing a Au nanostructure and a Zr/ZrOx thin film was developed. N2 gas was reduced to NH3 by using water as an electron donor through plasmon-induced charge separation under visible light irradiation.

19 Feb 12:52

Characterization of the Oxygen Binding Motif in a Ruthenium Water Oxidation Catalyst by Vibrational Spectroscopy

by Erin M. Duffy, Brett M. Marsh, Jonathan M. Voss, Etienne Garand


For homogeneous mononuclear ruthenium water oxidation catalysts, the Ru–O2 complex plays a crucial role in the rate determining step of the catalytic cycle, but the exact nature of this complex is unclear. Herein, the infrared spectra of the [Ru(tpy)(bpy)(O2)]2+ complex (tpy=2,2′:6′,2′′-terpyridine; bpy=2,2′-bipyridine) are presented. The complex [Ru(tpy)(bpy)(O2)]2+, formed by gas-phase reaction of [Ru(tpy)(bpy)]2+ with molecular O2, was isolated by using mass spectrometry and was directly probed by cryogenic ion IR predissociation spectroscopy. Well-resolved spectral features enable a clear identification of the O−O stretch using 18O2 substitution. The band frequency and intensity indicate that the O2 moiety binds to the Ru center in a side-on, bidentate manner. Comparisons with DFT calculations highlight the shortcomings of the B3LYP functional in properly depicting the Ru–O2 interaction.

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The O2 binding motif in the [Ru(tpy)(bpy)(O2)]2+ catalytic water oxidation intermediate is determined by using mass spectrometry and cryogenic ion IR predissociation spectroscopy. The O−O stretch, identified through 18O2 substitution, points to a singlet side-on bidentate O2 complex. A comparison of experimental results with those from calculations show that DFT may inaccurately describe the Ru–O2 interaction.

12 Feb 08:25

Cobalt salophen complexes for light-driven water oxidation

Catal. Sci. Technol., 2016, 6,4271-4282
DOI: 10.1039/C5CY02157J, Paper
Md. Ali Asraf, Hussein A. Younus, Chizoba I. Ezugwu, Akshay Mehta, Francis Verpoort
Earth-abundant molecular complexes have been found to be excellent catalysts for the light-driven water oxidation reaction.
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01 Feb 11:28

Recent advances in transition metal phosphide nanomaterials: synthesis and applications in hydrogen evolution reaction

Chem. Soc. Rev., 2016, 45,1529-1541
DOI: 10.1039/C5CS00434A, Tutorial Review
Yanmei Shi, Bin Zhang
This tutorial review provides an overview of recent development of TMP nanomaterials as catalysts for hydrogen generation with high activity and stability.
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14 Oct 09:10

Recent advances in energy transfer in bulk and nanoscale luminescent materials: from spectroscopy to applications

Chem. Soc. Rev., 2015, 44,8714-8746
DOI: 10.1039/C5CS00067J, Review Article
Xiaofeng Liu, Jianrong Qiu
We discuss optical energy transfer involving ions, QDs, molecules etc., together with the relevant applications in different areas.
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14 Oct 07:26

Bridging Efficiency within Multinuclear Homogeneous Catalysts in the Photocatalytic Reduction of Carbon Dioxide

by Simon Meister, Richard O. Reithmeier, Alexander Ogrodnik, Bernhard Rieger


A trinuclear complex consisting of one [Ru(dmb)3]2+ (dmb=4,4′-dimethyl-2,2′-bipyridine) (Ru) and two [Re(dmb)(CO)3Cl] (Re) building blocks, [Re(CO)3Cl(dmb−dmb)Ru(dmb)(dmb−dmb)Re(CO)3Cl](PF6)2 (ReRuRe), is presented. Photophysical properties of ReRuRe and the individual components with different or no covalent linkages are thoroughly investigated and compared. To elucidate the role of the single covalent bonds, photocatalytic reduction of CO2 is performed with the trinuclear complex and a series of model systems featuring systematic absence of linkages between the metal centers. Photoluminescence spectra and quantum yields reveal efficient energy transfer from the excited state of Re to Ru if these fragments are covalently linked. Moreover, intramolecular electron transfer from the one-electron reduced species of Ru to Re occurs if there is covalent bonding, leading to a higher photostability and thus the highest turnover number in photocatalytic CO2 reduction of 199 for the trinuclear complex ReRuRe within the systems under investigation. Optimized experimental conditions reveal the highest turnover number (315) reported to date for ReI/RuII-based homogeneous catalysts in photocatalytic CO2 reduction.

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The best things come in threes: A trinuclear ReI/RuII complex is presented with high photostability. We reveal a turnover number of 315, the highest reported to date for a ReI/RuII-based homogeneous catalyst in photocatalytic CO2 reduction. D=electron donor.

14 Oct 07:24

Template Design and Economical Strategy for the Synthesis of SSZ-13 (CHA-Type) Zeolite as an Excellent Catalyst for the Selective Catalytic Reduction of NOx by Ammonia

by Ruinian Xu, Runduo Zhang, Ning Liu, Biaohua Chen, Shi Zhang Qiao


SSZ-13 zeolite, a CHA-type aluminosilicate, has attracted wide attention recently because of its extraordinary physiochemical properties and excellent potential for applications in catalysis. In this work, SSZ-13 zeolite was synthesized using choline chloride as a CHA-topology construction template. This new template has a low cost and is environmentally friendly. Specifically it has the appropriate geometry and functional groups for easy self-assembly as dual molecules to form the CHA topology, which was verified by self-prepared organic templates with similar structure and functional groups as well as IR spectroscopy and DFT and potential energy distribution calculations. After ion exchange by Cu cations, the as-synthesized SSZ-13 exhibited an outstanding performance for the selective catalytic reduction of NO and showed ≈100 % NO conversions across a wide temperature window of 150–450 °C.

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The zeolite fantastic: Instead of the traditional high-cost and toxic N,N,N-trimethyl-1-1-adamantammonium hydroxide template, totally nontoxic and cheap choline chloride (a kind of vitamin B) is utilized as a structure- directing agent to synthesize SSZ-13 zeolite, a CHA-type aluminosilicate, which has an extraordinarily high and selective catalytic reduction activity for NOx removal.

14 Oct 06:26

Electrochemistry of Nanostructured Layered Transition-Metal Dichalcogenides

by Xinyi Chia, Alex Yong Sheng Eng, Adriano Ambrosi, Shu Min Tan and Martin Pumera

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Chemical Reviews
DOI: 10.1021/acs.chemrev.5b00287
14 Oct 06:26

Light-Driven Heterogeneous Reduction of Carbon Dioxide: Photocatalysts and Photoelectrodes

by James L. White, Maor F. Baruch, James E. Pander III, Yuan Hu, Ivy C. Fortmeyer, James Eujin Park, Tao Zhang, Kuo Liao, Jing Gu, Yong Yan, Travis W. Shaw, Esta Abelev and Andrew B. Bocarsly

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Chemical Reviews
DOI: 10.1021/acs.chemrev.5b00370
13 Oct 10:44

When Small is Big: The Role of Impurities in Electrocatalysis


Improvements in the fundamental understanding of electrocatalysis have started to revolutionize the development of electrochemical interfaces for the efficient conversion of chemical energy into electricity, as well as for the utilization of electrons to produce new chemicals that then can be re-used in energy conversion systems. Here, some facets of the role of trace level of impurities (from 10−7 to 10−6 M) in electrocatalysis of the oxygen reduction reaction, hydrogen oxidation and evolution reactions, and CO oxidation reactions are explored on well-characterized platinum single crystal surfaces and high surface area materials in alkaline and acidic environments. Of particular interest is the effect of anions (e.g., Cl, \( {\text{NO}}_{ 3}^{ - } \) ) and cations (i.e., Cu2+) present in the supporting electrolytes as well as surface defects (i.e., ad-islands) that are present on metal surfaces. The examples presented are chosen to demonstrate that a small level of impurities may play a crucial role in governing the reactivity of electrochemical interfaces.

13 Oct 10:43

Volcano Activity Relationships for Proton-Coupled Electron Transfer Reactions in Electrocatalysis


This paper studies simple kinetic models for proton-coupled electron transfer reactions, and demonstrates that for reactions in which proton and electron do not transfer simultaneously, pH dependence of the overall reaction rate is expected. In particular, if the current is evaluated on the reversible hydrogen scale, this may lead to volcano-type activity relations as a function of pH. In case that an acid–base equilibrium is part of the mechanism, the optimal pH occurs close to the pKa of this equilibrium.

16 Sep 06:40

A porous proton-relaying metal-organic framework material that accelerates electrochemical hydrogen evolution

by Idan Hod


Hydrogen evolution technologies for a future carbon-free energy economy require efficient catalysts which can be implemented on a large scale. Here, the authors prepare a composite electrode from readily available elements, whereby a metal-organic framework boosts catalytic performance by enabling rapid proton transport.

Nature Communications doi: 10.1038/ncomms9304

Authors: Idan Hod, Pravas Deria, Wojciech Bury, Joseph E. Mondloch, Chung-Wei Kung, Monica So, Matthew D. Sampson, Aaron W. Peters, Cliff P. Kubiak, Omar K. Farha, Joseph T. Hupp

16 Sep 06:39

Efficient direct solar-to-hydrogen conversion by in situ interface transformation of a tandem structure

by Matthias M. May


A future carbon-free energy economy requires an efficient photocatalytic route to hydrogen generation. Here, the authors employ surface modification techniques to raise the performance of an unassisted solar water splitting device to achieve exceptional performances.

Nature Communications doi: 10.1038/ncomms9286

Authors: Matthias M. May, Hans-Joachim Lewerenz, David Lackner, Frank Dimroth, Thomas Hannappel

20 Aug 07:53

Highly Robust Hydrogen Generation by Bioinspired Ir Complexes for Dehydrogenation of Formic Acid in Water: Experimental and Theoretical Mechanistic Investigations at Different pH

by Wan-Hui Wang, Mehmed Z. Ertem, Shaoan Xu, Naoya Onishi, Yuichi Manaka, Yuki Suna, Hide Kambayashi, James T. Muckerman, Etsuko Fujita and Yuichiro Himeda

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ACS Catalysis
DOI: 10.1021/acscatal.5b01090
19 Aug 14:07

Earth-abundant metal complexes as catalysts for water oxidation; is it homogeneous or heterogeneous?

Catal. Sci. Technol., 2015, 5,4901-4925
DOI: 10.1039/C5CY01251A, Minireview
Md. Ali Asraf, Hussein A. Younus, Mekhman Yusubov, Francis Verpoort
This minireview focuses on the aspects that determine whether particular catalysts for the oxidation of water are homogeneous or heterogeneous.
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19 Aug 14:04

Morphology and Active-Site Engineering for Stable Round-Trip Efficiency Li–O2 Batteries: A Search for the Most Active Catalytic Site in Co3O4

by Kyeongse Song, Eunbi Cho and Yong-Mook Kang

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ACS Catalysis
DOI: 10.1021/acscatal.5b01196
19 Aug 14:03

Reactivity and Mechanism Studies of Hydrogen Evolution Catalyzed by Copper Corroles

by Haitao Lei, Huayi Fang, Yongzhen Han, Wenzhen Lai, Xuefeng Fu and Rui Cao

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ACS Catalysis
DOI: 10.1021/acscatal.5b00666
19 Aug 13:58

A Molecular Copper Catalyst for Hydrogenation of CO2 to Formate

by Christopher M. Zall, John C. Linehan and Aaron M. Appel

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ACS Catalysis
DOI: 10.1021/acscatal.5b01646
19 Aug 13:58

α-Fe2O3/NiOOH: An Effective Heterostructure for Photoelectrochemical Water Oxidation

by Francesco Malara, Alessandro Minguzzi, Marcello Marelli, Sara Morandi, Rinaldo Psaro, Vladimiro Dal Santo and Alberto Naldoni

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ACS Catalysis
DOI: 10.1021/acscatal.5b01045
19 Aug 11:21

Active Sites for Light Driven Proton Reduction in Y 2 Ti 2 O 7 and CsTaWO 6 Pyrochlore Catalysts Detected by In Situ EPR


In situ EPR spectroscopy proved to be a versatile tool to identify active sites for photocatalytic hydrogen generation in modified Y2Ti2O7 and CsTaWO6 catalysts of pyrochlore structure, in which the metal cations are located in two different positions A and B. It was found that the B-sites exclusively occupied by titanium (Y2Ti2O7) and tantalum/tungsten (CsTaWO6) act as electron traps on the surface. From these sites, electron transfer to the co-catalysts proceeds. Thus, the B-sites are responsible for photocatalytic water reduction.

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19 Aug 11:16

EPR Spectroscopy as a Tool in Homogeneous Catalysis Research


In the context of homogeneous catalysis, open-shell systems are often quite challenging to characterize. Nuclear magnetic resonance (NMR) spectroscopy is the most frequently applied tool to characterize organometallic compounds, but NMR spectra are usually broad, difficult to interpret and often futile for the study of paramagnetic compounds. As such, electron paramagnetic resonance (EPR) has proven itself as a useful spectroscopic technique to characterize paramagnetic complexes and reactive intermediates. EPR spectroscopy is a particularly useful tool to investigate their electronic structures, which is fundamental to understand their reactivity. This paper describes some selected examples of studies where EPR spectroscopy has been useful for the characterization of open-shell organometallic complexes. The paper concentrates in particular on systems where EPR spectroscopy has proven useful to understand catalytic reaction mechanisms involving paramagnetic organometallic catalysts. The expediency of EPR spectroscopy in the study of organometallic chemistry and homogenous catalysis is contextualized in the introductory Sect. 1. Section 2 of the review focusses on examples of C–C and C–N bond formation reactions, with an emphasis on catalytic reactions where ligand/substrate non-innocence plays an important role. Both carbon and nitrogen centered radicals have been shown to play an important role in these reactions. A few selected examples of catalytic alcohol oxidation proceeding via related N-centered ligand radicals are included in this section as well. Section 3 covers examples of the use of EPR spectroscopy to study important commercial ethylene oligomerization and polymerization processes. In Sect. 4 the use of EPR spectroscopy to understand the mechanisms of Atom Transfer Radical Polymerization is discussed. While this review focusses predominantly on the application of EPR spectroscopy in mechanistic studies of C–C and C–N bond formation reactions mediated by organometallic catalysts, a few selected examples describing the application of EPR spectroscopy in other catalytic reactions such as water splitting, photo-catalysis, photo-redox-catalysis and related reactions in which metal initiated (free) radical formation plays a role are included as well. EPR spectroscopic investigation in this area of research are dominated by EPR spectroscopic studies in isotropic solution, including spin trapping experiments. These reactions are highlighted in Sect. 5. EPR spectroscopic studies have proven useful to discern the correct oxidation states of the active catalysts and also to determine the effective concentrations of the active species. EPR is definitely a spectroscopic technique that is indispensable in understanding the reactivity of paramagnetic complexes and in conjunction with other advanced techniques such as X-ray absorption spectroscopy and pulsed laser polymerization it will continue to be a very practical tool.

23 Jul 14:12

Water oxidation catalysed by iron complex of N,N[prime or minute]-dimethyl-2,11-diaza[3,3](2,6)pyridinophane. Spectroscopy of iron-oxo intermediates and density functional theory calculations

Chem. Sci., 2015, 6,5891-5903
DOI: 10.1039/C5SC01680K, Edge Article
Open Access Open Access
Creative Commons Licence&nbsp This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Wai-Pong To, Toby Wai-Shan Chow, Chun-Wai Tse, Xiangguo Guan, Jie-Sheng Huang, Chi-Ming Che
FeIV=O and/or FeV=O intermediates are suggested to be involved in water oxidation with [NH4]2[CeIV(NO3)6], NaIO4, or Oxone catalyzed by [FeIII(L1)Cl2]+ (1) on the basis of spectroscopic measurements and DFT calculations.
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22 Jul 14:10

Gold-Coated Cobalt Ferrite Nanoparticles via Methionine-Induced Reduction

by Agnė Mikalauskaitė, Rokas Kondrotas, Gediminas Niaura and Aru̅nas Jagminas

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The Journal of Physical Chemistry C
DOI: 10.1021/acs.jpcc.5b03528
22 Jul 14:07

Rechargeable Hydrogen Storage System Based on the Dehydrogenative Coupling of Ethylenediamine with Ethanol

by Peng Hu, Yehoshoa Ben-David, David Milstein


A novel and simple hydrogen storage system was developed, based on the dehydrogenative coupling of inexpensive ethylenediamine with ethanol to form diacetylethylenediamine. The system is rechargeable and utilizes the same ruthenium pincer catalyst for both hydrogen loading and unloading procedures. It is efficient and uses a low catalyst loading. Repetitive reversal reactions without addition of new catalyst result in excellent conversions in both the dehydrogenation and hydrogenation procedures in three cycles.

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In support of the hydrogen economy: An efficient and simple homogeneous hydrogen carrier system was developed based on the dehydrogenative coupling of ethylenediamine with ethanol to form diacetylethylenediamine. The same ruthenium pincer catalyst is used for both hydrogen loading and unloading reactions.

20 Jul 07:48

In Situ-Generated Co0-Co3O4/N-Doped Carbon Nanotubes Hybrids as Efficient and Chemoselective Catalysts for Hydrogenation of Nitroarenes

by Zhongzhe Wei, Jing Wang, Shanjun Mao, Diefeng Su, Haiyan Jin, Yihe Wang, Fan Xu, Haoran Li and Yong Wang

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ACS Catalysis
DOI: 10.1021/acscatal.5b00737
20 Jul 07:48

Organic Dye-Sensitized Tandem Photoelectrochemical Cell for Light Driven Total Water Splitting

by Fusheng Li, Ke Fan, Bo Xu, Erik Gabrielsson, Quentin Daniel, Lin Li and Licheng Sun

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Journal of the American Chemical Society
DOI: 10.1021/jacs.5b04856
17 Jul 12:13

A generic concept to overcome bandgap limitations for designing highly efficient multi-junction photovoltaic cells

by Fei Guo


The efficiency of a single-junction photovoltaic cell is constrained by the Shockley-Queisser limit. Here, the authors adopt a triple-junction configuration which relaxes material and current-matching constraints, providing a generic strategy for advancing the efficiency roadmap of photovoltaic technologies.

Nature Communications doi: 10.1038/ncomms8730

Authors: Fei Guo, Ning Li, Frank W. Fecher, Nicola Gasparini, Cesar Omar Ramirez Quiroz, Carina Bronnbauer, Yi Hou, Vuk V. Radmilović, Velimir R. Radmilović, Erdmann Spiecker, Karen Forberich, Christoph J. Brabec

17 Jul 12:11

Why we are teaching science wrong, and how to make it right

by M. Mitchell Waldrop

Why we are teaching science wrong, and how to make it right

Nature 523, 7560 (2015).

Author: M. Mitchell Waldrop

Active problem-solving confers a deeper understanding of science than does a standard lecture. But some university lecturers are reluctant to change tack.

17 Jul 12:11

Lifelong learning: Science professors need leadership training

by Charles E. Leiserson

Lifelong learning: Science professors need leadership training

Nature 523, 7560 (2015). doi:10.1038/523279a

Authors: Charles E. Leiserson & Chuck McVinney

To drive discovery, scientists heading up research teams large and small need to learn how people operate, argue Charles E. Leiserson and Chuck McVinney.

17 Jul 08:31

Perovskite Solar Cells with Near 100% Internal Quantum Efficiency Based on Large Single Crystalline Grains and Vertical Bulk Heterojunctions

by Bin Yang, Ondrej Dyck, Jonathan Poplawsky, Jong Keum, Alexander Puretzky, Sanjib Das, Ilia Ivanov, Christopher Rouleau, Gerd Duscher, David Geohegan and Kai Xiao

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Journal of the American Chemical Society
DOI: 10.1021/jacs.5b03144