The recent advances in electrocatalysis for oxygen reduction reaction (ORR) for proton exchange membrane fuel cells (PEMFCs) are thoroughly reviewed. This comprehensive Review focuses on the low- and non-platinum electrocatalysts including advanced platinum alloys, core–shell structures, palladium-based catalysts, metal oxides and chalcogenides, carbon-based non-noble metal catalysts, and metal-free catalysts. The recent development of ORR electrocatalysts with novel structures and compositions is highlighted. The understandings of the correlation between the activity and the shape, size, composition, and synthesis method are summarized. For the carbon-based materials, their performance and stability in fuel cells and comparisons with those of platinum are documented. The research directions as well as perspectives on the further development of more active and less expensive electrocatalysts are provided.

http://repository.ust.hk/ir/bitstream/1783.1-77094/1/acs.chemrev.5b00462_withlink.pdf

Recent Advances in Electrocatalysts for Oxygen Reduction Reaction

This article provides an up-to-date perspective on the use of anion-exchange membranes in fuel cells, electrolysers, redox flow batteries, reverse electrodialysis cells, and bioelectrochemical systems (e.g. microbial fuel cells). The aim is to highlight key concepts, misconceptions, the current state-of-the-art, technological and scientific limitations, and the future challenges (research priorities) related to the use of anion-exchange membranes in these energy technologies. All the references that the authors deemed relevant, and were available on the web by the manuscript submission date (30th April 2014), are included.

/pdf/anion-exchange-membranes-in-electrochemical-energy-systems-46uquenb56.pdf

Anion-exchange membranes in electrochemical energy systems

The development of low-cost, efficient, and stable electrocatalysts for the oxygen reduction reaction (ORR) is desirable but remains a great challenge. Herein, we made a highly reactive and stable isolated single-atom Fe/N-doped porous carbon (ISA Fe/CN) catalyst with Fe loading up to 2.16 wt %. The catalyst showed excellent ORR performance with a half-wave potential (E1/2) of 0.900 V, which outperformed commercial Pt/C and most non-precious-metal catalysts reported to date. Besides exceptionally high kinetic current density (Jk) of 37.83 mV cm−2 at 0.85 V, it also had a good methanol tolerance and outstanding stability. Experiments demonstrated that maintaining the Fe as isolated atoms and incorporating nitrogen was essential to deliver the high performance. First principle calculations further attributed the high reactivity to the high efficiency of the single Fe atoms in transporting electrons to the adsorbed OH species.

Isolated Single Iron Atoms Anchored on N-Doped Porous Carbon as an Efficient Electrocatalyst for the Oxygen Reduction Reaction

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

High-performance electrode materials are the key to advances in the areas of energy conversion and storage (e.g., fuel cells and batteries). In this Review, recent progress in the synthesis and electrochemical application of transition metal carbides (TMCs) and nitrides (TMNs) for energy storage and conversion is summarized. Their electrochemical properties in Li-ion and Na-ion batteries as well as in supercapacitors, and electrocatalytic reactions (oxygen evolution and reduction reactions, and hydrogen evolution reaction) are discussed in association with their crystal structure/morphology/composition. Advantages and benefits of nanostructuring (e.g., 2D MXenes) are highlighted. Prospects of future research trends in rational design of high-performance TMCs and TMNs electrodes are provided at the end.

/pdf/transition-metal-carbides-and-nitrides-in-energy-storage-and-33qhnc07u1.pdf

Transition Metal Carbides and Nitrides in Energy Storage and Conversion

The electrocatalytic application of RuO2 in direct borohydride fuel cells

LaNi0.8Co0.2O3 as a cathode catalyst for a direct borohydride fuel cell

Ultrafine amorphous Co–W–B alloy as the anode catalyst for a direct borohydride fuel cell

Energy internet, digital economy, and green economic growth: Evidence from China

Corruption and market segmentation generally result from inter-regional resource allocation mechanism at the level of government and market, and it is of great significance to clarify their effects on haze pollution for the healthy development of the regional economy. With theoretical analysis, this paper applies systematic GMM to examine the impact of corruption on haze pollution. The mediatory effect model is used to further evaluate the mediatory effect of market segmentation by using panel data for 30 provinces in China from 2006 to 2018. The evaluations reveal that corruption positively affects haze pollution at the 1% significance level and has a prominent “time inertia”. After alleviation of the endogenous problem and a series of robustness tests, this conclusion remains valid. Based on national samples, corruption, especially environmental corruption, not only directly provokes an increase in haze pollution, but also aggravates it through market segmentation, and, the impact of corruption on haze pollution in different regions and at different periods has significant heterogeneity. Therefore, policymakers should start from the institutional mechanism to curb haze pollution by improving the performance appraisal system. Moreover, the synergistic effect between anti-corruption and governance on the environment should be enhanced by improving the anti-corruption management system. Local protectionism should be eliminated to promote the integration of regional markets. A unified, open and organized market system should be established to form the synergy of governance on the environment.

Xiaodong Yang

Papers

The electrocatalytic application of RuO2 in direct borohydride fuel cells

LaNi0.8Co0.2O3 as a cathode catalyst for a direct borohydride fuel cell

Ultrafine amorphous Co–W–B alloy as the anode catalyst for a direct borohydride fuel cell

Energy internet, digital economy, and green economic growth: Evidence from China

Corruption, market segmentation and haze pollution: empirical evidence from China