New catalysts of Ni−Fe loading Ni foam (Ni−Fe/NF) were used in catalytic reforming of pyrrole for the co-production of H 2 and CNTs@Ni foam electrode materials. Ni−Fe/NF with different Fe/ Ni ratios (0.5, 1, 2, and 3) and Ni/NF and Fe/NF catalysts were tested. The Ni−Fe alloy was formed on Ni−Fe/NF and remarkably promoted pyrrole conversion and H 2 yield. They showed a trend of first increasing and then decreasing with the increase of the Fe/Ni ratio, and the N1F2/ NF (Fe/Ni ratio is 2) reached the maximum. The H 2 yield over N1F2/ NF was 20 times larger than that over Ni/NF and Fe/NF. The high amount of Fe−Ni alloy with a small crystallite size boosted the catalytic activity of Ni−Fe/NF. After the reforming reaction, large amounts of CNTs were observed on the surface of Ni foam's skeleton network. The structures of CNTs@Ni foam were prepared and promoted by the Ni− Fe alloy. It proved that the CNTs on Ni−Fe/NF catalysts follow the tip-growth and vapor−liquid−solid (VLS) mechanisms. The Ni−Fe alloy contributed to the formation of liquid carbide and carbon intermediates, thus promoting the CNTs' growth. Compared with the pristine Ni foam, the prepared CNTs@Ni foam materials showed excellent electrochemical performance and had promising application potential in supercapacitors. The spent N1F1/NF (Fe/Ni ratio is 1) showed the best charging and discharging capacity.

No abstract

Volatile organic compounds (VOCs) in cooking oil fumes need to be efficiently removed due to the significant damage they cause to the environment and human health. This review discusses the emission characteristics, which are influenced by different cooking temperatures, cooking oils, and cuisines. Then, various cooking oil fume purification methods are mainly classified into physical capture, chemical decomposition, and combination methods. VOCs removal rate, system operability, secondary pollution, application area, and cost are compared. The catalytic combustion method was found to have the advantages of high VOC removal efficiency, environmental protection, and low cost. Therefore, the last part of this review focuses on the research progress of the catalytic combustion method and summarizes its mechanisms and catalysts. The Marse-van Krevelen (MVK), Langmuir-Hinshelwood (L-H), and Eley-Rideal (E-R) mechanisms are analyzed. Noble metal and non-noble metal catalysts are commonly used. The former showed excellent activity at low temperatures due to its strong adsorption and electron transfer abilities, but the high price limits its application. The transition metals primarily comprise the latter, including single metal and composite metal catalysts. Compared to single metal catalysts, the interaction between metals in composite metal catalysts can further enhance the catalytic performance.