Promoton effect of lanthanum on the Co/La/Ba ammonia synthesis catalysts - the influence of lanthanum content

Magdalena Zybert , Aleksandra Tarka , Bogusław Mierzwa , Leszek Kępiński , Wioletta Raróg-Pilecka

Abstract

The effect of lanthanum content on catalytic properties of cobalt catalysts for ammonia synthesis has been studied. The amount of La in the studied catalysts ranged from 0-55.7 wt.%, whereas the barium content was constant (approx. 1.5 mmol gCo-1). The characterization studies included a determination of properties of the catalysts precursors (N2 physisorption, XRPD), as well as the catalysts in the active form (TPR-MS, XRPD, SEM-EDX and H2 chemisorption). The activity of the obtained Co/La/Ba catalysts in NH3 synthesis was tested in a flow differential reactor operating under conditions close to the industrial ones (p=6.3 MPa, T=400°C, H2/N2=3:1). It has been found that lanthanum plays the role of an effective structural promoter. However, there is a strong correlation between the La content in the catalysts and their properties: increasing amount of lanthanum is accompanied by the improvement in textural properties of both the precursors and catalysts in the reduced form. Lanthanum does not work as an activator for the cobalt surface. The increase in the activity of Co/La/Ba catalysts was observed as a result of a development of the active phase surface by increasing the La content.
Author Magdalena Zybert KTCh
Magdalena Zybert,,
- Chair of Chemical Technology
, Aleksandra Tarka KTCh
Aleksandra Tarka,,
- Chair of Chemical Technology
, Bogusław Mierzwa
Bogusław Mierzwa,,
-
, Leszek Kępiński
Leszek Kępiński,,
-
, Wioletta Raróg-Pilecka KTCh
Wioletta Raróg-Pilecka,,
- Chair of Chemical Technology
Journal seriesApplied Catalysis A-General, ISSN 0926-860X
Issue year2016
Vol515
Pages16-24
Publication size in sheets0.5
Keywords in Englishammonia synthesis, cobalt catalyst, promoter, lanthanum content
DOIDOI:10.1016/j.apcata.2016.01.036
URL http://www.sciencedirect.com/science/article/pii/S0926860X16300369
Languageen angielski
File
Appl. Catal A 515 (5016) 16.pdf (file archived - login or check accessibility on faculty) Appl. Catal A 515 (5016) 16.pdf 2.9 MB
Score (nominal)40
ScoreMinisterial score = 40.0, 28-11-2017, ArticleFromJournal
Ministerial score (2013-2016) = 40.0, 28-11-2017, ArticleFromJournal
Publication indicators WoS Impact Factor: 2016 = 4.339 (2) - 2016=4.354 (5)
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