scholarly journals Industrially Produced Fe- and Mn-Based Perovskites: Effect of Synthesis on Reactivity in Three-Way Catalysis: Part 1

ACS Omega ◽  
2021 ◽  
Vol 6 (38) ◽  
pp. 24325-24337
Author(s):  
Elena Brusamarello ◽  
Cataldo Blonda ◽  
Cristina Salazar-Castro ◽  
Andrea Eva Pascui ◽  
Paolo Canu ◽  
...  
ACS Omega ◽  
2021 ◽  
Author(s):  
Elena Brusamarello ◽  
Cataldo Blonda ◽  
Cristina Salazar-Castro ◽  
Paolo Canu ◽  
Antonella Glisenti

Author(s):  
Chen Liqing ◽  
Liu Zuqin ◽  
Zhang Wei

Valence state analyses of Fe and Mn in oxides by EPMA have been reported in literature. In this paper, the effects of valence state on intensity ratios ILα/IKα and ILα/ILβ of Cu, Ni, Co, Fe, Mn, Cr and their oxides, and on intensity ratios ILβ2/ILα1 and ILγ1/ILα1 of Mo, Nb, Zr and their oxides were studied. It was observed that intensity ratios change with valence states in accordance with some regularities, and these effects could be utilized for analyzing the valence states of catalysts.Valence state analysis of elements by EPMA is based on the fact that changes in the states of valence electrons in the outer shells of an atom cause corresponding changes in line intensities. The M electrons of Cu, Ni, Co, Fe, Mn, Cr and the N electrons of Mo, Nb, Zr are valence electrons. Line Kα1,2 and six lines of L are produced from the transitions of K-L2,3 and L-M or L-N respectively.


2010 ◽  
Vol 31 (1) ◽  
pp. 100-105
Author(s):  
Ming TIAN ◽  
Xiaodong WANG ◽  
Yanyan ZHU ◽  
Junhu WANG ◽  
Tao ZHANG
Keyword(s):  

2018 ◽  
Vol 1093 ◽  
pp. 012013 ◽  
Author(s):  
Anugrah Ricky Wijaya ◽  
Ida Farida ◽  
Atik Sakbaniah ◽  
Anisa Mai Rahmawati ◽  
Endang Budiasih ◽  
...  
Keyword(s):  

1975 ◽  
Vol 55 (6) ◽  
pp. 1006-1008 ◽  
Author(s):  
Seshadri Kannan ◽  
Benedict Joseph
Keyword(s):  

2020 ◽  
Vol 27 (12) ◽  
pp. 1678-1686 ◽  
Author(s):  
Shi-yuan Liu ◽  
Yu-lan Zhen ◽  
Xiao-bo He ◽  
Li-jun Wang ◽  
Kuo-chih Chou

2021 ◽  
Vol 6 (1) ◽  
pp. 14
Author(s):  
Liudmila Demina ◽  
Irina Gablina ◽  
Olga Dara ◽  
Dmitry Budko ◽  
Nina Gorkova ◽  
...  

We examined the distribution of Fe, Mn, Cu, Zn, and Pb in one core of metalliferous, and one core of non-mineralized (background) carbonate sediments (located 69 km northwards), from the Pobeda hydrothermal field. Mechanisms of metal accumulation in sediments (12 samples) were evaluated based on sequential extraction of geochemical fractions, including mobile (exchangeable complex, authigenic Fe-Mn hydroxides, and sulfides), and lithogenic (fixed in crystalline lattices) forms. Maps of element distribution in sediment components were obtained using a scanning electron microscope equipped with an energy-dispersive spectrometry detector. In metalliferous sediments, according to X-ray diffraction data, the main Fe mineral phase was goethite FeOOH (37–44% on a carbonate-free basis). The contents of Fe and Mn reached 31.6 and 0.18%, respectively, whereas concentrations of Cu, Zn and Pb were 0.98, 0.36, and 0.059%. The coefficient of metal enrichment relative to background values varied from 16 to 125 times. The exception was Mn, for which no increased accumulation was recorded. Essential mass of Fe (up to 70% of total content) was represented by the residual fraction composed of crystallized goethite, aluminosilicates, the minerals derived from bedrock destruction processes. Among geochemically mobile fractions, 90–97% of total Fe was found in the form of authigenic oxyhydroxides. The same fraction was the predominant host for Mn in both metalliferous and background sediments (55–85%). A total of 40–96 % of Cd, Cu, Zn, and Pb were associated with these Fe and Mn fractions. The sulfide fraction amounted to roughly 10% of each metal. In metalliferous sediment core, the maximum concentrations of metals and their geochemically mobile fractions were recorded in deeper core intercepts, an observation that might be attributed to influence of hydrothermal diffused fluids. Our data suggested that metals are mostly accumulated in carbonate sediments in their contact zone with the underlying serpentinized basalts.


2021 ◽  
Vol 616 ◽  
pp. 118100
Author(s):  
Narasimharao Katabathini ◽  
Islam Hamdy Abd El Maksod ◽  
Mohamed Mokhtar
Keyword(s):  

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