Natural gas serves as a crucial bridge fuel in the green transition of the energy and transportation sectors and is expected to remain pivotal for their long-term sustainable operation. However, uncontrolled emissions of methane—its principal component—intensify the greenhouse effect. Since mobile sources represent a key focus in air pollution control and noble metals have demonstrated decades of proven effectiveness in exhaust gas purification, this paper systematically reviews representative studies on eight noble metals (Pd, Pt, Rh, Ir, Ru, Os, Ag, and Au) for the catalytic abatement of methane emissions. It discusses the potential impact of exhaust gas composition on methane catalytic oxidation activity, explains factors influencing the activity and deactivation of noble metal catalysts, and emphasizes efforts to mitigate catalyst deactivation caused by two key poisons: water and sulfur. By offering an in-depth understanding of the challenges in designing and fabricating high-efficiency methane combustion catalysts, this review aims to facilitate the advancement of methane emission control technologies for lean-burn mobile sources.
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Open Access
Review Article
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Open Access
Research Article
Issue
Bimetallic catalysts are extensively utilized in heterogeneous catalysis due to their superior performance. The catalytic efficiency of these catalysts is influenced by various factors, particularly their structure and active sites, which are often overlooked in terms of mechanism and evolution. Herein, we present AuCuO/Al2O3, which feature active CuO island structures on its surface, demonstrating exceptional catalytic oxidative dehydrogenation performance with isopropanol. Compared with untreated AuCu/Al2O3, AuCuO/Al2O3 shows significantly enhanced activity, with nearly an order of magnitude improvement in catalytic performance at low temperatures. This enhancement is attributed to the element segregation process and the positive effect of Cu structures on catalytic activity. Theoretical simulations reveal that Cu and Au elements migrate in opposite directions, leading to the formation of CuO islands. In-situ transmission electron microscopy (TEM) images under oxidizing and thermal conditions elucidated the evolution of these structures. This work uncovers the evolution mechanism of active structures and interfaces in bimetallic catalysts, offering insights into the construction of interfacial sites and optimization of catalyst structures for high-performance applications.
Open Access
Review
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Ammonia serves as a viable medium for hydrogen storage owing to its significant hydrogen content and elevated energy density, and the absence of carbon dioxide emissions during ammonia-to-hydrogen production has inspired more research on ammonia decomposition. Despite growing interest, a significant gap persists between the depth of existing studies and the practical approach to on-the-spot hydrogen generation using ammonia decomposition. The creation of effective and accessible catalysts to feed ammonia decomposition is a critical step in addressing this daunting challenge. This paper systematically summarizes four key catalyst design strategies, including size effect, alkalinity modulation, metal–support interactions, and alloying, informed by experimental and theoretical investigations into ammonia decomposition. Each strategy's underlying mechanism for enhancing ammonia decomposition is elucidated in detail. Moreover, the paper categorizes catalysts employed in existing ammonia decomposition reactors to guide future catalyst development. The influence of diverse energy sources and reactor configurations on catalyst performance is also discussed to provide a comprehensive framework for advancing ammonia decomposition catalyst research.
Open Access
Research Article
Issue
In recent years, with increasingly scarce land resources, incineration technology has gradually become the mainstream disposal method of household hazardous waste. The exhaust gas of incineration contains both NOx and chlorine-containing volatile organic compounds (CVOCs), which will cause air pollution and serious harm to human health. The synergetic purification of NOx and CVOCs has huge ecological environment and economic benefits. Therefore, it is necessary to design a dual-effect catalyst to eliminate NOx and CVOCs simultaneously. In this work, we prepared CeO2-based catalysts doped with different metal cations by co-precipitation method. The physical and chemical properties of the catalysts were characterized by a variety of characterization methods. The catalytic activity of the catalysts for the synergistic oxidation of chlorobenzene and reduction of NOx was evaluated, and the reaction mechanism was explored. We found that Cr–Ce sample showed good synergistic catalytic activity and stability. The strong redox performance of Cr species not only improved the NOx reduction and CVOC oxidation capacity of CeO2, but also solved the problem of chlorination poisoning of pure CeO2.
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