In situ M�ssbauer spectroscopic characterization of Fe/AI2O3 and Fe/ThO2 Fischer-Tropsch catalysts

Vaishnava, P. P.; Ktorides, Petros I.; Montano, P. A.; Mbadcam, Ketcha Joseph; Melson, Gordon A.

doi:10.1016/0021-9517(85)90301-x

Cited by 27 publications

(3 citation statements)

References 17 publications

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“…Vaishnava and Montano applied in situ Möessbauer spectroscopy to study the phase evolution of FeCl 3 intercalated in graphite layers [90,92] as well as Fe/Al 2 O 3 and Fe/ThO 2 [93] during reduction and exposure to FT conditions. The applied cell varies from the one reported by Lázár et al and Delgass et al [31,37].…”

Section: Mössbauer Spectroscopymentioning

confidence: 99%

In situ characterization of Fischer–Tropsch catalysts: a review

Fischer

Claeys

2020

J. Phys. D: Appl. Phys.

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In the field of heterogeneous catalysis research, in situ and operando characterization techniques, i.e. characterization techniques which can be applied under realistic reaction conditions and ideally on a working catalyst, become essential in order to generate new knowledge and understanding of structure performance relationships. Only this knowledge will enable researchers to develop or rather design new catalysts for existing and novel processes without relying on an ‘educated guess’ approach. In combination with ever improving theoretical predictions, operando characterization techniques are expected to be the main drivers in catalyst research and associated material science in the foreseeable future. Fischer–Tropsch (FT) catalyst systems, and specifically the iron based catalysts, are highly dynamic under reaction conditions, making deductions on structure-activity relationships difficult when relying on conventional characterization techniques. In addition, various deactivation mechanisms, such as oxidation, poisoning, sintering, attrition and phase separation have been observed. As such, the FT synthesis encompasses several challenges experienced in some form or other in most catalytic applications and material science studies. The present review therefore aims to provide a comprehensive account of characterization techniques employed under (quasi) in situ and operando conditions for FT catalysts. Together with a description of the respective technique and a critical discussion of the employed reaction cell, the actual research conducted is briefly discussed. We hope that this combination will enable readers not only to get a good impression of the capabilities and limitations of the respective technique and available instrumentation but also to understand their applicability in catalysis research and maybe to be inspired to push current boundaries.

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Section: Mössbauer Spectroscopymentioning

confidence: 99%

In situ characterization of Fischer–Tropsch catalysts: a review

Fischer

Claeys

2020

J. Phys. D: Appl. Phys.

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“…Neste sistema, deseja-se evitar a formação de compostos de Fe e alumínio, do tipo FeAlz04 e AhFe206 [22]. A presença de tais compostos dificultaria a conversão total dos compostos de ferro para a-Fe, quando do tratamento térmico sob atmosfera de hidrogênio de alta pureza, como bem demostrado em trabalhos relacionados com a síntese de catalisadores e/ou suporte de catalisadores [5,22,[32][33][34][35][36][37][38]. A presença, porém, de uma tal fase de Fe e AI pode apresentar interessantes e desejados efeitos de aumento da coercividade do sistema.…”

Section: Escolha E Preparação Dos Precursores Metálicosunclassified

“…Na Série A, como mostra a Tabela Vlll, o aumento da temperatura de calcinação privilegia a transformação das fases intermediárias da alumina para a fase estável a-Ah03, sem haver formação da fase FeAh04, uma fase possível para o sistema Fe-Ah03 [22,33]. Até a temperatura de calcinação de 800 °C predominam fases intermediárias de alumina com baixíssimo grau de cristalinidade.…”

Section: Difratometria De Raios X Das Amostras Calcinadasunclassified

Sintese e caracterização do solido granular magnetico Fe-Al2O3

Santos¹

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Fluxograma do processamento sol-gel aplicado na obtenção do sólido granular 26 Fe-Ah03. 2 Principais diferenças de processamento entre as três séries de amostras de 27 Fe-Alz03. Visualização gráfica das condições de redução dos óxidos de F e para Fe metálico 27 aplicadas nas três séries de amostras Fe-Ah03. Di:fratogramas das amostras secas da Série B: (a) BA; (b) BB; (c) BC; (d) BD; e 34 (e) BE. SA = (NH4)zS04 e M = rnagnetita. Di:fratogramas das amostras secas da Série C: (a) CA; (b) CB; (c) CC; (d) CD; e (e) CE. N4==(NH4)4(N03)zS04, N5=(NH4)5(N03)3S04, N A = 0 3 , SA=(NH4)2S04 e FN=NIIJ'e(S04)z. 35 Espectros Mõssbauer a 300 K do material seco da Série A com frações volumétri-37 cas crescentes de Fe total, amostras: (a) AA; (b) AB; e (c) AC. Espectros Mõssbauer a 300 K do material seco da Série B com frações volumétri-38 cas crescentes de Fe total, amostras: (a) BA; (b) BB; (c) BC; (d) BD; e (e) BE. Espectros Mõssbauer a 300 K do material seco da Série C com frações volumétri-39 cas crescentes de Fe total, amostras: (a) CA; (b) CB; (c) CC; (d) CD; e (e) CE Espectros Mõssbauer a 300 K do material seco da Série C, amostra CD, com fra-43 ção volumétrica de Fe total de 51,3 %:(a) a 300 K e (b) a 20 K 10 Di:fratogramas das amostras calcinadas da Série B: (a) BAC; (b) BBC; (c) BCC; 45 (d) BDC; e (e) BEC. F= a-Fez03 e AI= a-Ah03. 11 Di:fratogramas das amostras calcinadas a 300 °C da Série C: (a) CA3; (b) CB3; (c) 48 CC3; (d) CD3; e (e) CE3. TS = N1:4AI(S04)z12Hz0, NF = NIIJ'e(S04)2, F= a-Fe203, MG = y-Fe203 e CH = Fe1403(S04)Is63H20. 12 Difratogramas das amostras calcinadas a 600 °C da Série C: (a) CA6; (b) CB6; (c) 49 CC6; (d) CD6; e (e) CE6. AG = Al2(S04)317H20 e F= a-Fez03.

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ChemInform Abstract: In Situ Mössbauer Spectroscopic Characterization of Fe/Al₂O₃ and Fe/ThO₂ Fischer‐Tropsch Catalysts.

Vaishnava¹,

Ktorides²,

Montano³

et al. 1986

Chemischer Informationsdienst

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In situ M�ssbauer spectroscopic characterization of Fe/AI2O3 and Fe/ThO2 Fischer-Tropsch catalysts

Cited by 27 publications

References 17 publications

In situ characterization of Fischer–Tropsch catalysts: a review

In situ characterization of Fischer–Tropsch catalysts: a review

Sintese e caracterização do solido granular magnetico Fe-Al2O3

ChemInform Abstract: In Situ Mössbauer Spectroscopic Characterization of Fe/Al₂O₃ and Fe/ThO₂ Fischer‐Tropsch Catalysts.

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In situ M�ssbauer spectroscopic characterization of Fe/AI2O3 and Fe/ThO2 Fischer-Tropsch catalysts

Cited by 27 publications

References 17 publications

In situ characterization of Fischer–Tropsch catalysts: a review

In situ characterization of Fischer–Tropsch catalysts: a review

Sintese e caracterização do solido granular magnetico Fe-Al2O3

ChemInform Abstract: In Situ Mössbauer Spectroscopic Characterization of Fe/Al2O3 and Fe/ThO2 Fischer‐Tropsch Catalysts.

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ChemInform Abstract: In Situ Mössbauer Spectroscopic Characterization of Fe/Al₂O₃ and Fe/ThO₂ Fischer‐Tropsch Catalysts.