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.

The oxidation of methanol (CH3OH) on hydroxylated monoclinic zirconia (H-m-ZrO2 (− 1 1 1)) surface has been studied using slab periodic model and density functional theory. Both terminal- and bridging-type mechanisms were examined on the basis of two possible adsorption modes between CH3OH and hydroxyl groups (terminal and bridging) on H-m-ZrO2 (− 1 1 1) surface. The calculation results show that the whole catalytic cycle can be marked by three reaction stages: the formation of CH3O via the decomposition of CH3OH (Stage I), the formation of HCOO via the oxidation of CH3O (Stage II), and the CO formation and regeneration of hydroxyl groups (Stage III). Taking potential energy surface (PES) into account, the bridging-type mechanism appeared to be the preferred one (CH3OH → CH3O → CH2O → H2COO → HCOO → CO). The rate-determining step is identified to be the transformation of H2COO to HCOO and H2O with a barrier of 1.42 eV. The calculated results of this work should be useful in the search and design of new catalysts.

The oxidation of methanol on hydroxylated m-ZrO2(− 1 1 1): a first-principles study

In this work, a series of colloidal gold nanoparticles with controllable sizes were anchored on carbon nanotubes (CNT) for the aerobic oxidation of benzyl alcohol. The intrinsic influence of Au particles on the catalytic behavior was unraveled based on different nanoscale-gold systems. The Au/CNT-A sample with smaller Au sizes deserved a faster reaction rate, mainly resulting from the higher dispersion degree (23.5%) of Au with the available exposed sites contributed by small gold particles. However, monometallic Au/CNT samples lacked long-term stability. CeO2 was herein decorated to regulate the chemical and surface structure of the Au/CNT. An appropriate CeO2 content tuned the sizes and chemical states of Au by electron delivery with better metal dispersion. Small CeO2 crystals that were preferentially neighboring the Au particles facilitated the generation of Au–CeO2 interfaces, and benefited the continuous supplementation of oxygen species. The collaborative functions between the size effect and surface chemistry accounted for the higher benzaldehyde yield and sustainably stepped-up reaction rates by Au-Ce5/CNT with 5 wt% CeO2.

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Boosting the catalytic behavior and stability of a gold catalyst with structure regulated by ceria

RESEARCH NOTE Graphitic Nanofilaments as Novel Support of Ru-Ba Catalysts for Ammonia Synthesis

Highly-dispersed noble metal nanoparticles (Au, Ag, Pd and Pt) supported on silica have been successfully prepared via reaction between modified silica and metal precursors in aqueous solutions, and the modified silica was synthesised through a sol–gel process of tetraethyl orthosilicate and 3-glycidoxypropyltrimethoxysilane (GPTMS) with aqueous ammonia as condensation catalyst. The transmission electron microscopy and X-ray diffraction results show that the noble metal particles are at nanoscale with good uniformity, and the diol species derived from 3-glycidoxypropyl groups of GPTMS are confirmed to serve as the reductants for metal precursors by solid state nuclear magnetic resonance spectra. The combination of noble metal nanoparticles and organic groups retained on silica would make the materials possess some special properties.

Facile in situ preparation of noble metal nanoparticles supported on silica

The classic acrylonitrile (AN) electrohydrodimerization (EHD) to adiponitrile (ADN) process produces oxygen on the anode side. The oxygen evolution reaction (OER) is energy consuming, and O2 is of low value and has security issues while directly contacting with organic molecules. Herein, by replacing OER with 5-hydroxymethylfurfural oxidation reaction (HMFOR), we report paired electrolysis of AN and HMF for simultaneous generation of ADN and 2,5-furandicarboxylic acid (FDCA). On the anode side, the electrodeposited amorphous NiMoP film-covered nickel foam efficiently boosted HMFOR activity by enlarging the electrochemically active surface area (ECSA) via in situ selective removal of Mo and P on the surface. On the cathode side, addition of dimethylformamide (DMF) as a cosolvent enhanced the reaction efficiency of ANEHD by forming a single-phase electrolyte that offers better interaction between AN and the electrode. The ANEHD–HMFOR paired system shows excellent generation rates of FDCA (0.018 gFDCA·h−1·cm−2) and ADN (0.017 gADN·h−1·cm−2) at a high cell current (160 mA). An amount of 1 kWh of electricity can produce 2.91 mol of ADN and 0.53 mol of FDCA with 107.1% Faraday efficiency.

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Changhai Liang

Papers

The oxidation of methanol on hydroxylated m-ZrO2(− 1 1 1): a first-principles study

Boosting the catalytic behavior and stability of a gold catalyst with structure regulated by ceria

RESEARCH NOTE Graphitic Nanofilaments as Novel Support of Ru-Ba Catalysts for Ammonia Synthesis

Facile in situ preparation of noble metal nanoparticles supported on silica

Paired Electrolysis of Acrylonitrile and 5-Hydroxymethylfurfural for Simultaneous Generation of Adiponitrile and 2,5-Furandicarboxylic Acid