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A class of non-precious metal Co, N, S tri-doped carbon (Co/NSC) electrocatalyst for oxygen reduction reaction (ORR) is synthesized from earth-abundant high-sulfur inferior raw coal as the single N, S and C precursor by a two-step co-pyrolysis method. High-sulfur raw coal derived N, S co-doped carbon (NSC) and direct co-pyrolysis coal with CoCl2 (coal-Co) are also prepared for comparison. The as-prepared Co/NSC has an amorphous carbon structure and is doped with heteroatoms N, S and Co nanoparticles in the carbon matrix. Furthermore, compared with NSC, S content decreases obviously and N content mainly in the form of pyrrolic-N changes little in Co/NSC. The as-prepared Co/NSC exhibits a more excellent ORR electrocatalytic activity than that of NSC and coal-Co in terms of the onset potential, ORR peak potential, the half-wave potential, the limiting-diffusion current density and the predominantly 4-electron transfer pathway in 0.1 M KOH. Based on these results, some possibilities attributing to the enhanced performance of Co/NSC are also explained. This two-step co-pyrolysis process is also demonstrated a green utilization of high-sulfur raw coal. [ABSTRACT FROM AUTHOR]

Understanding the nature of electrode materials used in clean energy conversion systems is very important for promoting the comercialization of these systems. Herein, we investigate the essential characteristics of nondoped electrodes for oxygen reduction reaction (ORR) and supercapacitor applications based on three typical types of carbon materials, namely, carbon nanotubes (CNTs, one-dimensional), graphene (G, two-dimensional) and carbon black (BP2000, three-dimensional) by using the corroborated physical characterizations and electrochemical measurements. Several insights are obtained from the relationship between the microstructure and electrochemical performance: (1) the ORR electrocatalytic activity is mainly related to the O content rather than to the specific surface area and the defect degree; (2) G has the largest specific capacitance, most likely due to a better electrical conductivity and its unique two-dimensional microstructure rather than its O content, specific surface area and defect degree. This work confirms that different types of carbon materials are suitable for different applications: CNTs are advantageous for the ORR applications, while G is a promising electrode material for supercapacitor applications. [ABSTRACT FROM AUTHOR]

A questionnaire was used to survey the knowledge and attitude of senior managers toward dioxins at five waste incineration plants and seven coking plants. A field survey was performed to verify dioxin control practices at two of the waste incineration plants and one of the coke plants. All the respondents at the waste incineration plants claimed to be knowledgeable about dioxins and had a proactive attitude toward dioxin control. The field survey verified the implementation of various dioxin control measures at their plants. However, the coking plants' respondents were ignorant about dioxins. This study reveals that dioxin emission policies have had a significant effect on industrial practices and knowledge. The differences in economics between the two sites have also contributed to the disparity in their respective knowledge levels. Finally, the paper gives the corresponding recommendations on how to further improve the level of dioxin knowledge and control practices in China. [ABSTRACT FROM AUTHOR]