Structure and Surface Chemistry of Industrial Ammonia Synthesis Catalysts

Stoltze, Per

doi:10.1007/978-3-642-79197-0_2

Cited by 5 publications

(3 citation statements)

References 409 publications

(850 reference statements)

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“…The active components may be either metals or the oxides themselves. This approach was very fruitful for understanding the surface physics and reactivity of “complex” systems such as Pd/Al 2 O 3 ,6, 181c, 189 Au on diverse carriers14c, 25a, 31b, 190 or supported vanadium oxides 161c. 191 Catalytic reactions were observed, such as the oxidation of methanol or the hydrogenation of alkynes, under conditions that permitted an analysis of the structure of the active components.…”

Section: Catalysts Are Not Staticmentioning

confidence: 99%

Heterogeneous Catalysis

2015

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Section: Catalysts Are Not Staticmentioning

confidence: 99%

Heterogeneous Catalysis

2015

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“…Structural promoters primarily increase the catalyst's activity by increasing the surface area of an active phase. Electronic (chemical) promoters increase the catalytic activity by modifying the active metal and by increasing the reaction rate per surface area [5,6]. This is a general description, but the function of each promoter is always specific to the particular catalytic system and the particular reaction.…”

Section: Introductionmentioning

confidence: 99%

“…S BET -specific surface area estimated based on the BET isotherm model 4. S R -specific surface area estimated based on the BET isotherm model after hydrogen activation 5. V P -total pore volume estimated based on the BJH isotherm model.…”

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confidence: 99%

On Optimal Barium Promoter Content in a Cobalt Catalyst for Ammonia Synthesis

et al. 2022

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High priority in developing an efficient cobalt catalyst for ammonia synthesis involves optimizing its composition in terms of the content of promoters. In this work, a series of cobalt catalysts doubly promoted with cerium and barium was prepared and tested in ammonia synthesis (H2/N2 = 3, 6.3 MPa, 400 °C). Barium content was studied in the range of 0–2.6 mmol gCo−1. Detailed characterization studies by nitrogen physisorption, SEM-EDX, XRPD, H2-TPR, and H2-TPD showed the impact of barium loading in CoCeBa catalysts on the physicochemical properties and activity of the catalysts. The most pronounced effect was observed in the development of the active phase surface, a differentiation of weakly and strongly binding sites on the catalyst surface and changes in cobalt surface activity (TOF). Barium content in the range of 1.1–1.6 mmol gCo−1 leads to obtaining a catalyst with the most favorable properties. Its excellent catalytic performance is ascribed to the appropriate Ba/Ce molar ratio, i.e., greater than unity, which results in not only a structural promotion of barium, but also a modifying action associated with the in-situ formation of the BaCeO3 phase.

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