and Fuels Changzhi Li,† Xiaochen Zhao,† Aiqin Wang,† George W. Huber,†,‡ and Tao Zhang*,† †State Key Laborotary of Catalysis, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China ‡Department of Chemical and Biological Engineering, University of WisconsinMadison, Madison, Wisconsin 53706, United States

Catalytic Transformation of Lignin for the Production of Chemicals and Fuels

Spinels with the formula of AB2O4 (where A and B are metal ions) and the properties of magnetism, optics, electricity, and catalysis have taken significant roles in applications of data storage, biotechnology, electronics, laser, sensor, conversion reaction, and energy storage/conversion, which largely depend on their precise structures and compositions. In this review, various spinels with controlled preparations and their applications in oxygen reduction/evolution reaction (ORR/OER) and beyond are summarized. First, the composition and structure of spinels are introduced. Then, recent advances in the preparation of spinels with solid-, solution-, and vapor-phase methods are summarized, and new methods are particularly highlighted. The physicochemical characteristics of spinels such as their compositions, structures, morphologies, defects, and substrates have been rationally regulated through various approaches. This regulation can yield spinels with improved ORR/OER catalytic activities, which can furth...

Spinels: Controlled Preparation, Oxygen Reduction/Evolution Reaction Application, and Beyond

Catalysts for chemical and electrochemical reactions underpin many aspects of modern technology and industry, from energy storage and conversion to toxic emissions abatement to chemical and materials synthesis. This role necessitates the design of highly active, stable, yet earth-abundant heterogeneous catalysts. In this Review, we present the perovskite oxide family as a basis for developing such catalysts for (electro)chemical conversions spanning carbon, nitrogen, and oxygen chemistries. A framework for rationalizing activity trends and guiding perovskite oxide catalyst design is described, followed by illustrations of how a robust understanding of perovskite electronic structure provides fundamental insights into activity, stability, and mechanism in oxygen electrocatalysis. We conclude by outlining how these insights open experimental and computational opportunities to expand the compositional and chemical reaction space for next-generation perovskite catalysts.

http://science.sciencemag.org/content/sci/358/6364/751.full.pdf

Perovskites in catalysis and electrocatalysis

Polymer nanocomposites possess promising high performances as engineering materials, if they are prepared and fabricated properly. Some work has been recently done on such polymer nanocomposites as dielectrics and electrical insulation. This was reviewed in 2004 based on the literatures published up to 2003. New significant findings have been added since then. Furthermore, a multi-core model with the far-distance effect, which is closely related to an "interaction zones", has been proposed from consideration of mesoscopic analysis of electrical and chemical structures of an existing interface with finite thickness. It is speculatively examined in the paper how the model works for various properties and phenomena already found in nanocomposites as dielectrics focusing on electrical characteristics, resistance to high voltage environment, and thermal properties.

Dielectric nanocomposites with insulating properties

Polymer nanocomposites are defined as polymers in which small amounts of nanometer size fillers are homogeneously dispersed by only several weight percentages. Addition of just a few weight percent of the nanofillers has profound impact on the physical, chemical, mechanical and electrical properties of polymers. Such change is often favorable for engineering purpose. This nanocomposite technology has emerged from the field of engineering plastics, and potentially expanded its application to structural materials, coatings, and packaging to medical/biomedical products, and electronic and photonic devices. Recently these 'hi-tech' materials with excellent properties have begun to attract research people in the field of dielectrics and electrical insulation. Since new properties are brought about from the interactions of nanofillers with polymer matrices, mesoscopic properties are expected to come out, which would be interesting to both scientists and engineers. Improved characteristics are. expected as dielectrics and electrical insulation. Several interesting results to indicate the foreseeable future have been revealed, some of which are described on materials and processing in the paper together with basic concepts and future direction.

Polymer nanocomposites as dielectrics and electrical insulation-perspectives for processing technologies, material characterization and future applications

Titanium diboride is the most promising candidate material for development of wettable cathodes for aluminum smelting. It is considered as an alternative for carbon cathodes in order to reduce the anode cathode distance resulting in higher energy efficiency in electrolysis cells. In this work, TiB2-based ceramic specimens were consolidated using metallic additives followed by pressureless sintering. Different proportions of iron and titanium (≤ 10 wt%) were used as low melting point sintering additives. Sintering was conducted at 1400–1650°C under controlled atmosphere. The effects of composition, sintering temperature, milling time and pre-alloying of the additives on densification, microstructure, and mechanical properties were investigated. It was found that pre-alloying and milling time have significant influence on densification, microstructure uniformity and bending strength. Uniform crack-free microstructure with even distribution of pores as well as maximum relative density of 91% and bending strength of 300 MPa were obtained using pre-alloyed additives, milling time of 30 min and sintering for 1 h at 1650°C.

Pressureless Sintering of TiB2-Based Composites Using Ti and Fe Additives for Development of Wettable Cathodes

The invention relates to a process for the production of elemental boron. The process of the invention comprises subjecting a mixture of a reducible boron compound and a reducing agent to mechanical activation, whereby the boron compound is reduced to elemental boron by the reducing agent. When the reducible boron compound contains sodium, the reducing agent is used in combination with a salt thereof in order to enable the desired solid state reaction to occur. Such a process enables one to produce elemental boron at low cost.

Process for the production of elemental boron by solid state reaction

Aluminium production process: from Hall–Héroult to modern smelters

Adding TiC particles into iron aluminide coatings has been found to improve its wear resistance, but its corrosion behavior is less known. In this study, the corrosion behavior of Fe3Al/TiC and Fe3Al-Cr/TiC composite coatings, prepared by high velocity oxy fuel (HVOF) spraying, was studied in 3.5 wt. % NaCl solution by means of electrochemical techniques and surface analysis. Results revealed that adding TiC particles into Fe3Al matrix to improve the wear resistance does not deteriorate the corrosion behavior of Fe3Al coating. It was also showed that addition of chromium to Fe3Al/TiC composite provides a more protective layer.

https://corpus.ulaval.ca/jspui/bitstream/20.500.11794/34464/1/OA_Met_2019.pdf

Houshang Alamdari

Papers

Pressureless Sintering of TiB2-Based Composites Using Ti and Fe Additives for Development of Wettable Cathodes

Process for the production of elemental boron by solid state reaction

Aluminium production process: from Hall–Héroult to modern smelters

Electrochemical corrosion behavior of Fe3Al/TiC and Fe3Al-Cr/TiC coatings prepared by HVOF in NaCl solution

Inspection of baked carbon anodes using a combination of multi-spectral acousto-ultrasonic techniques and principal component analysis.