2.3. Evaluation of Photocatalytic Water Splitting 6507 2.3.1. Photocatalytic Activity 6507 2.3.2. Photocatalytic Stability 6507 3. UV-Active Photocatalysts for Water Splitting 6507 3.1. d0 Metal Oxide Photocatalyts 6507 3.1.1. Ti-, Zr-Based Oxides 6507 3.1.2. Nb-, Ta-Based Oxides 6514 3.1.3. W-, Mo-Based Oxides 6517 3.1.4. Other d0 Metal Oxides 6518 3.2. d10 Metal Oxide Photocatalyts 6518 3.3. f0 Metal Oxide Photocatalysts 6518 3.4. Nonoxide Photocatalysts 6518 4. Approaches to Modifying the Electronic Band Structure for Visible-Light Harvesting 6519

Semiconductor-based Photocatalytic Hydrogen Generation

Rod Borup is a Team Leader in the fuel cell program at Los Alamos National Lab in Los Alamos, New Mexico. He received his B.S.E. in Chemical Engineering from the University of Iowa in 1988 and his Ph.D. from the University of Washington in 1993. He has worked on fuel cell technology since 1994, working in the areas of hydrogen production and PEM fuel cell stack components. He has been awarded 12 U.S. patents, authored over 40 papers related to fuel cell technology, and presented over 50 oral papers at national meetings. His current main research area is related to water transport in PEM fuel cells and PEM fuel cell durability. Recently, he was awarded the 2005 DOE Hydrogen Program R&D Award for the most significant R&D contribution of the year for his team's work in fuel cell durability and was the Principal Investigator for the 2004 Fuel Cell Seminar (San Antonio, TX, USA) Best Poster Award. Jeremy Meyers is an Assistant Professor of materials science and engineering and mechanical engineering at the University of Texas at Austin, where his research focuses on the development of electrochemical energy systems and materials. Prior to joining the faculty at Texas, Jeremy workedmore » as manager of the advanced transportation technology group at UTC Power, where he was responsible for developing new system designs and components for automotive PEM fuel cell power plants. While at UTC Power, Jeremy led several customer development projects and a DOE-sponsored investigation into novel catalysts and membranes for PEM fuel cells. Jeremy has coauthored several papers on key mechanisms of fuel cell degradation and is a co-inventor of several patents. In 2006, Jeremy and several colleagues received the George Mead Medal, UTC's highest award for engineering achievement, and he served as the co-chair of the Gordon Research Conference on fuel cells. Jeremy received his Ph.D. in Chemical Engineering from the University of California at Berkeley and holds a Bachelor's Degree in Chemical Engineering from Stanford University. Bryan Pivovar received his B.S. in Chemical Engineering from the University of Wisconsin in 1994. He completed his Ph.D. in Chemical Engineering at the University of Minnesota in 2000 under the direction of Profs. Ed Cussler and Bill Smyrl, studying transport properties in fuel cell electrolytes. He continued working in the area of polymer electrolyte fuel cells at Los Alamos National Laboratory as a post-doc (2000-2001), as a technical staff member (2001-2005), and in his current position as a team leader (2005-present). In this time, Bryan's research has expanded to include further aspects of fuel cell operation, including electrodes, subfreezing effects, alternative polymers, hydroxide conductors, fuel cell interfaces, impurities, water transport, and high-temperature membranes. Bryan has served at various levels in national and international conferences and workshops, including organizing a DOE sponsored workshop on freezing effects in fuel cells and an ARO sponsored workshop on alkaline membrane fuel cells, and he was co-chair of the 2007 Gordon Research Conference on Fuel Cells. Minoru Inaba is a Professor at the Department of Molecular Science and Technology, Faculty of Engineering, Doshisha University, Japan. He received his B.Sc. from the Faculty of Engineering, Kyoto University, in 1984 and his M.Sc. in 1986 and his Dr. Eng. in 1995 from the Graduate School of Engineering, Kyoto University. He has worked on electrochemical energy conversion systems including fuel cells and lithium-ion batteries at Kyoto University (1992-2002) and at Doshisha University (2002-present). His primary research interest is the durability of polymer electrolyte fuel cells (PEFCs), in particular, membrane degradation, and he has been involved in NEDO R&D research projects on PEFC durability since 2001. He has authored over 140 technical papers and 30 review articles. Kenichiro Ota is a Professor of the Chemical Energy Laboratory at the Graduate School of Engineering, Yokohama National University, Japan. He received his B.S.E. in Applied Chemistry from the University of Tokyo in 1968 and his Ph.D. from the University of Tokyo in 1973. He has worked on hydrogen energy and fuel cells since 1974, working on materials science for fuel cells and water electrolysis. He has published more than 150 original papers, 70 review papers, and 50 scientific books. He is now the president of the Hydrogen Energy Systems Society of Japan, the chairman of the Fuel Cell Research Group of the Electrochemical Society of Japan, and the chairman of the National Committee for the Standardization of the Stationary Fuel Cells. ABSTRACT TRUNCATED« less

Scientific aspects of polymer electrolyte fuel cell durability and degradation.

Graphene, emerging as a true 2-dimensional material, has received increasing attention due to its unique physicochemical properties (high surface area, excellent conductivity, high mechanical strength, and ease of functionalization and mass production). This article selectively reviews recent advances in graphene-based electrochemical sensors and biosensors. In particular, graphene for direct electrochemistry of enzyme, its electrocatalytic activity toward small biomolecules (hydrogen peroxide, NADH, dopamine, etc.), and graphenebased enzyme biosensors have been summarized in more detail; Graphene-based DNA sensing and environmental analysis have been discussed. Future perspectives in this rapidly developing field are also discussed.

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Graphene Based Electrochemical Sensors and Biosensors: A Review

Because of the remarkably high theoretical energy output, metal–air batteries represent one class of promising power sources for applications in next-generation electronics, electrified transportation and energy storage of smart grids. The most prominent feature of a metal–air battery is the combination of a metal anode with high energy density and an air electrode with open structure to draw cathode active materials (i.e., oxygen) from air. In this critical review, we present the fundamentals and recent advances related to the fields of metal–air batteries, with a focus on the electrochemistry and materials chemistry of air electrodes. The battery electrochemistry and catalytic mechanism of oxygen reduction reactions are discussed on the basis of aqueous and organic electrolytes. Four groups of extensively studied catalysts for the cathode oxygen reduction/evolution are selectively surveyed from materials chemistry to electrode properties and battery application: Pt and Pt-based alloys (e.g., PtAu nanoparticles), carbonaceous materials (e.g., graphene nanosheets), transition-metal oxides (e.g., Mn-based spinels and perovskites), and inorganic–organic composites (e.g., metal macrocycle derivatives). The design and optimization of air-electrode structure are also outlined. Furthermore, remarks on the challenges and perspectives of research directions are proposed for further development of metal–air batteries (219 references).

Metal–air batteries: from oxygen reduction electrochemistry to cathode catalysts

Advances in the development of novel cobalt Fischer-Tropsch catalysts for synthesis of long-chain hydrocarbons and clean fuels.

Highly efficient catalysts play an important role in the effective use of biomass oil to produce clean fuel. In this work, pure-phase Ni−Mo bimetallic nitrides (Ni2Mo3N and Ni3Mo3N) with different stoichiometric ratios are prepared by temperature-programmed nitridation of the metal oxide precursors in ammonia, which are investigated in the hydrodeoxygenation of methyl palmitate in the fixed-bed reactor at moderate conditions. The physical and chemical properties of catalysts were evaluated by H2-TPR, XRD, SEM, TEM, XPS, and CO chemisorption. The Ni2Mo3N catalyst presents the best methyl palmitate hydrogenation activity (con.%=95.4 %) and the maximum hexadecane selectivity (95.0 %), which is obviously higher than those of Ni3Mo3N and Mo2N catalysts. By introducing transition metal Ni into the Mo2N lattice to form nickel-molybdenum bimetallic nitride, the lattice structure and electronic structure of the Mo active center have been changed, which greatly enhances the hydrodeoxygenation performances for the transformation of biomass oil to clean fuel. 

Nickel molybdenum bimetallic nitrides as efficient catalysts for hydrodeoxygenation of methyl palmitate

Cyclohexane dicarboxylic acid (CHDA) ester, a kind of environmental-friendly plasticizer, can be produced by phthalates hydrogenation. However, the synthesis of catalysts with high activity and selectivity is a challenge due to the stability of aromatic rings. In this work, a series of ultrauniform Ru nanoclusters supported by γ-Al2O3 are synthesized for the hydrogenation of diisononyl phthalate (DINP). Results show that the conversion of DINP and the selectivity of diisononyl-cyclohexane-1,2-dicarboxylate (DINCH) both reach 100% at 140 °C and 3 MPa H2 pressure. Diisononyl-cyclohexene-1,2-dicarboxylate (4H-DINP) and 1,2-cyclohexanedicarboxylate-7-methyloctyl ester are found; the hydrogenation reaction network of DINP is constructed. Alkali metal ions adsorbed on the surface of Ru nanoclusters prepared by the polyol method can stabilize Ru3+-Hδ− species by electrostatic interaction, thus affecting the hydrogenation activity of the catalyst, following the order of Li+ > Na+ > K+ > Cs+. Ru-based catalysts prepared by the polyol method have good prospects for application in phthalates hydrogenation. 

Ultrauniform Ru Nanoclusters as Efficient Hydrogenation Catalysts for Phthalates

The present study was designed to investigate the role of miR‐708‐5p/p38 mitogen‐activated protein kinase (MAPK) pathway during the mechanism of selenium nanoparticles (Nano‐Se) against nickel (Ni)‐induced testosterone synthesis disorder in rat Leydig cells. We conducted all procedures based on in vitro culture of rat primary Leydig cells. After treating Leydig cells with Nano‐Se and NiSO4 alone or in combination for 24 h, we determined the cell viability, reactive oxygen species (ROS) levels, testosterone production, and the protein expression of key enzymes involved in testosterone biosynthesis: steroidogenic acute regulatory (StAR) and cytochrome P450 cholesterol side chain cleavage enzyme (CYP11A1). The results indicated that Nano‐Se antagonized cytotoxicity and eliminated ROS generation induced by NiSO4, suppressed p38 MAPK protein phosphorylation and reduced miR‐708‐5p expression. Importantly, we found that Nano‐Se upregulated the expression of testosterone synthase and increased testosterone production in Leydig cells. Furthermore, we investigated the effects of p38 MAPK and miR‐708‐5p using their specific inhibitor during Nano‐Se against Ni‐induced testosterone synthesis disorder. The results showed that Ni‐inhibited testosterone secretion was alleviated by Nano‐Se co‐treatment with p38 MAPK specific inhibitor SB203580 and miR‐708‐5p inhibitor, respectively. In conclusion, these findings suggested Nano‐Se could inhibit miR‐708‐5p/p38 MAPK pathway, and up‐regulate the key enzymes protein expression for testosterone synthesis, thereby antagonizing Ni‐induced disorder of testosterone synthesis in Leydig cells.

Selenium nanoparticles improve nickel‐induced testosterone synthesis disturbance by down‐regulating miR‐708‐5p/p38 MAPK pathway in Leydig cells

The carbonylative transformation of ethylene oxide (EO) into methyl 3-hydroxypropionate (3-HPM) is a key process for the production of 1,3-propanediol (1,3-PDO), which is currently viewed as one of the most promising monomers and intermediates in polyester and pharmaceuticals industry. In this work, a homogeneous reaction system using commercial Co2(CO)8 was first studied for the carbonylation of EO to 3-HPM. The catalytic behavior was related to the electronic environment of N on aromatic rings of ligands, where N with rich electron density induced a stronger coordination with Co center and higher EO transformation. A reaction order of 2.1 with respect to EO and 0.3 with respect to CO was unraveled based on the kinetics study. The 3-HPM yield reached 91.2% at only 40°C by Co2(CO)8 coordinated with 3-hydroxypyridine. However, Co-containing colloid was formed during the reaction, causing the tough separation and impossible recycling of samples. Concerning the sustainable utilization, Co particles immobilized on pre-treated carbon nanotubes (Co/CNT-C) were designed via an in situ reduced colloid method. It is remarkable that unlike conventional Co/CNT, Co/CNT-C was highly selective toward the transformation of EO to 3-HPM with a specific rate of 52.2 mmol·g Co - 1 ·h - 1 , displaying a similar atomic efficiency to that of coordinated Co2(CO)8. After reaction, the supported Co/CNT-C catalyst could be easily separated from the liquid reaction mixture, leading to a convenient cyclic utilization.

Chemical kinetics and promoted Co-immobilization for efficient catalytic carbonylation of ethylene oxide into methyl 3-hydroxypropionate

Developing efficient electrocatalysts with high activity and stability for oxygen evolution reaction (OER) is of crucial importance. Herein, carbon shell encapsulated ultrafine FeNiOx NPs with an average size of 2.32 nm uniformly dispersing on CNT (denoted as FeNiOx@C-CNT) was synthesized via a simple laser irradiation technique. The as-prepared FeNiOx@C-CNT composites present excellent electrocatalytic OER activity, mainly owing to the small size and high dispersion of FeNiOx NPs. Electrochemical measurement show that these composites possess a low overpotential of 267 mV at 10 mA cm−2 as well as a small tafel slope of 46.29 mV dec−1. Additionally, encapsulation in the carbon shell effectively preserve the FeNiOx NPs from degrading under the harsh external condition, showing almost unfading electrocatalytic activity after 20,000 potential cycles. Importantly, this strategy is universal and could be extended to synthesis other type of carbon shell encapsulated metal-based material (e.g. FeOx@C-CNT, CoOx@C-CNT, NiOx@C-CNT and MnOx@C-CNT), which might provide a new way to design high-efficiency electrocatalysts. 

Changhai Liang

Papers

Nickel molybdenum bimetallic nitrides as efficient catalysts for hydrodeoxygenation of methyl palmitate

Ultrauniform Ru Nanoclusters as Efficient Hydrogenation Catalysts for Phthalates

Selenium nanoparticles improve nickel‐induced testosterone synthesis disturbance by down‐regulating miR‐708‐5p/p38 MAPK pathway in Leydig cells

Chemical kinetics and promoted Co-immobilization for efficient catalytic carbonylation of ethylene oxide into methyl 3-hydroxypropionate

Laser irradiation synthesized carbon encapsulating ultrafine transition metal nanoparticles for highly efficient oxygen evolution