There is still an ongoing effort to search for sustainable, clean and highly efficient energy generation to satisfy the energy needs of modern society. Among various advanced technologies, electrocatalysis for the oxygen evolution reaction (OER) plays a key role and numerous new electrocatalysts have been developed to improve the efficiency of gas evolution. Along the way, enormous effort has been devoted to finding high-performance electrocatalysts, which has also stimulated the invention of new techniques to investigate the properties of materials or the fundamental mechanism of the OER. This accumulated knowledge not only establishes the foundation of the mechanism of the OER, but also points out the important criteria for a good electrocatalyst based on a variety of studies. Even though it may be difficult to include all cases, the aim of this review is to inspect the current progress and offer a comprehensive insight toward the OER. This review begins with examining the theoretical principles of electrode kinetics and some measurement criteria for achieving a fair evaluation among the catalysts. The second part of this review acquaints some materials for performing OER activity, in which the metal oxide materials build the basis of OER mechanism while non-oxide materials exhibit greatly promising performance toward overall water-splitting. Attention of this review is also paid to in situ approaches to electrocatalytic behavior during OER, and this information is crucial and can provide efficient strategies to design perfect electrocatalysts for OER. Finally, the OER mechanism from the perspective of both recent experimental and theoretical investigations is discussed, as well as probable strategies for improving OER performance with regards to future developments.

Electrocatalysis for the oxygen evolution reaction: recent development and future perspectives

Renewable Resources Robert-Jan van Putten,†,‡ Jan C. van der Waal,† Ed de Jong,*,† Carolus B. Rasrendra,‡,⊥ Hero J. Heeres,*,‡ and Johannes G. de Vries* †Avantium Chemicals, Zekeringstraat 29, 1014 BV Amsterdam, the Netherlands ‡Department of Chemical Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands DSM Innovative Synthesis BV, P.O. Box 18, 6160 MD Geleen, the Netherlands Department of Chemical Engineering, Institut Teknologi Bandung, Ganesha 10, Bandung 40132, Indonesia

Hydroxymethylfurfural, A Versatile Platform Chemical Made from Renewable Resources

Although sunlight-driven water splitting is a promising route to sustainable hydrogen fuel production, widespread implementation is hampered by the expense of the necessary photovoltaic and photoelectrochemical apparatus. Here, we describe a highly efficient and low-cost water-splitting cell combining a state-of-the-art solution-processed perovskite tandem solar cell and a bifunctional Earth-abundant catalyst. The catalyst electrode, a NiFe layered double hydroxide, exhibits high activity toward both the oxygen and hydrogen evolution reactions in alkaline electrolyte. The combination of the two yields a water-splitting photocurrent density of around 10 milliamperes per square centimeter, corresponding to a solar-to-hydrogen efficiency of 12.3%. Currently, the perovskite instability limits the cell lifetime.

http://science.sciencemag.org/content/sci/345/6204/1593.full.pdf

Water photolysis at 12.3% efficiency via perovskite photovoltaics and Earth-abundant catalysts

A review on the utilization of fly ash

Water electrolysis is considered as the most promising technology for hydrogen production. Much research has been devoted to developing efficient electrocatalysts for hydrogen production via the hydrogen evolution reaction (HER) and oxygen production via the oxygen evolution reaction (OER). The optimum electrocatalysts can drive down the energy costs needed for water splitting via lowering the overpotential. A number of cobalt (Co)-based materials have been developed over past years as non-noble-metal heterogeneous electrocatalysts for HER and OER. Recent progress in this field is summarized here, especially highlighting several important bifunctional catalysts. Various approaches to improve or optimize the electrocatalysts are introduced. Finally, the current existing challenges and the future working directions for enhancing the performance of Co-implicated electrocatalysts are proposed.

Recent Progress in Cobalt‐Based Heterogeneous Catalysts for Electrochemical Water Splitting

Synthesis of mesoporous alumina with tunable structural properties

This study examined the influence of an iron-based homogeneous combustion catalyst on the oxidative behaviour and nanostructural characteristics of soot emitted from a single-cylinder compression ignition engine. The catalyst was homogeneously added into a commercial diesel as the reference at ultra low dosage ratios. Smoke opacity was measured using a smoke opacimeter in the engine exhaust stream to indicate the overall soot emission intensity. Soot particles were also sampled while the engine was maintained in steady-state operations and fuelled with the reference diesel and the catalyst treated fuels, respectively. The soot samples were subjected to thermogravimetric analysis (TGA) to study their oxidation reactivities in air, and transmission electron microscopy (TEM) for morphological characterisations. The smoke opacity results showed 7.3–39.5% less soot emissions when the catalyst was applied, depending on the catalyst dosage ratio. The TGA results revealed that soot from the catalyst treated fuels possessed higher oxidative reactivity as indicated by ignition at lower temperatures and faster oxidation rates than those of soot from the reference diesel. This tendency was more remarked as the catalyst dosage ratio increased. Subsequent TEM imaging analyses observed that the irregularly shaped, aggregated soot particles were made of a number of spherical primary particles. Smaller and more narrowly-distributed primary soot particles with the catalyst treated fuels than those of the reference diesel were evident. High-resolution TEM imaging revealed graphitic crystallite structures of the soot samples from both catalyst-treated and -untreated fuels with no obvious variations in the nuclei core areas, suggesting that the internal structure of the soot was not affected by the catalyst. It was evident that iron ions from the catalyst were more involved in the soot oxidation process, rather than in the early soot formation stage, and eventually resulted in smaller and narrowly-distributed primary soot particles.

/pdf/nanostructure-and-oxidative-properties-of-soot-from-a-8u7qps6avn.pdf

Nanostructure and oxidative properties of soot from a compression ignition engine: The effect of a homogeneous combustion catalyst

A novel Fe2O3–MnO2/TiO2 catalyst was synthesized using a conventional impregnation method assisted with ethylene glycol and used for NH3–SCR. The catalyst exhibited superior low-temperature activity over a broad temperature window (100–325 °C), low apparent activation energy, and excellent sulfur-poisoning resistance. The characterization results revealed that the catalyst was greatly dispersed with smaller particles, and the partial doping of Fe into the TiO2 lattice thereby led to the formation of the Fe–O–Ti structure, which could strengthen the electronic inductive effect and increase the ratio of surface chemisorption oxygen, resulting in the enhancement of NO oxidation and favoring the low-temperature SCR activity via a “fast SCR” process. The in situ FTIR analysis showed that the NOx adsorption capacity was significantly improved due to the desired dispersion property, further helping both the SCR activity and reaction rate at low temperatures. The present work confirmed that more active sites can ...

Dongke Zhang

Papers

Synthesis of mesoporous alumina with tunable structural properties

Nanostructure and oxidative properties of soot from a compression ignition engine: The effect of a homogeneous combustion catalyst

Enhancement of Low-Temperature Catalytic Activity over a Highly Dispersed Fe–Mn/Ti Catalyst for Selective Catalytic Reduction of NOx with NH3

Multi-fluid reactive modeling of fluidized bed pyrolysis process

Behaviour of inorganic constituents and ash characteristics during fluidised-bed combustion of several Australian low-rank coals