Propylene is an important petrochemical feedstock, second only to ethylene in terms of importance. With ever-increasing demand, there is a pressing need to explore alternative production methods. Of these, propane dehydrogenation (PDH) is by far the most promising solution.
Due to their cost-effectiveness and eco-friendly characteristics, Ni-based catalysts have gained abundant attention from researchers in a number of catalytic applications, including hydrogenation, methane reforming, electrochemical processes, and photocatalysis. However, nickel’s role in the dehydrogenation of alkanes in maximum temperatures has been little explored.
This is basically due to the tendency of nickel species to pass through reliefs to form nickel metal (NP) nanoparticles under harsh reaction conditions. Such transformations can lead to significant dehydrogenation and compromise selectivity in the process.
The emergence of single-atom catalysts (SACs) represents a revolutionary progression in catalysis, with widespread application in catalytic processes. However, its application in the dehydrogenation of mild hydrocarbons at maximum temperatures has so far been somewhat limited.
In propane dehydrogenation, the activation of C-H bonds has little sensitivity to catalyst structure. However, adverse reactions such as hydrolysis, isomerization, and coking are typical structure-sensitive reactions that require the involvement of steel atoms. Therefore, SACs with remote dispersion steel active centers offer transparent benefits in suppressing those side reactions, positioning them as promising candidates for catalytic dehydrogenation of alkanes.
The monatomic catalyst of Ni in Anatase TiO2 (Ni1/A-TiO2) has recently shown surprising intrinsic activity and propylene selectivity, as well as much higher stability than the corresponding Ni(NP) nanoparticle catalyst (NiNP/A-TiO2) in the PDH reaction at 580 °C, according to a study team led by Professor Botao Qiao of the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences.
The production rate of propylene in Ni1/A-TiO2 is about 1. 96 molC3H6. gNi-1. h-1, more than 65 times that of the NiNP/A-TiO2 standard (0. 03 molC3H6. gNi-1. h-1).
By combining the characterizations HAADT-STEM, CO-DRIFTS in situ, XPS in situ, and XAS, the researchers demonstrated that the Ni SAC basically comprises individual Ni atoms dispersed separately in a positive Ni(II) valence state. These atoms primarily serve as active centers rather than selling the formation of coordinated sites of unsaturated Ti ions.
In addition, due to the strong metal-carrier interaction between the reduced conditions of Ni NPs and TiO2 carriers, the Ni nanoparticle sites were encapsulated through a TiOx overlay (approximately 2 nm thick), showing lower initial propane conversion and durability.
This painting highlights the merit of single-atom catalysts with isolated active sites in PDH reactions and provides a reference for long-term studies on SAC preparation and application. The results were published in the Chinese Journal of Catalysis.
Zhang, Q. , et al. (2024) Catalytic dehydrogenation of propane using anatase-supported single-atom Ni catalysts. Chinese Journal of Catalysis. is what je. org/10. 1016/s1872-2067(23)64584-x
Source: http://english. dicp. cas. cn/
Hello, my name is Azthena, can you accept with me to locate advertising clinical answers in AZoNetwork. com.
A few things you want to know before you get started. Please read and agree to continue.
Super. Ask your question.
Read the full terms and conditions.
AZoM. com – An AZoNetwork site
Owned and operated through AZoNetwork, © 2000-2024