In situ and ex situ Moessbauer spectroscopy studies of iron phthalocyanine adsorbed on high surface area carbon

Cr(vi) reduction is performed by BiOCl0.8Br0.2 composite produced via a facile in situ synthetic process at room temperature while making use of PVP (Mw = 10 000).

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Novel Base Catalysts by Nitridation of Zeolite Y: Characterization and Catalytic Evaluation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.148-149.1096 ◽

2010 ◽

Vol 148-149 ◽

pp. 1096-1099

Author(s):

Gong Ming Peng ◽

De Lian Yi ◽

Lin Wu ◽

Zhao Hui Ou Yang ◽

Jian Guo Wang

Keyword(s):

Surface Area ◽

Zeolite Y ◽

High Surface ◽

High Surface Area ◽

Diethyl Malonate ◽

Bet Surface Area ◽

In Situ Drifts ◽

Base Catalysts ◽

Diffuse Reflectance Infrared

Novel base catalysts were obtained by subjecting Y zeolites to nitridation. These materials were characterized by elemental analysis, X-ray diffraction, BET surface area analysis, In situ diffuse reflectance infrared fourier transform Spectroscopy (in situ DRIFTS), Pyrrole adsorption. The results indicated nitrogen-incorporated NaY zeolite was well ordered and possess high surface area and pore volume. In situ DRIFTS experiments confirmed that N atoms had been introduced into the framework by nitridation to form -NH2- or -NH- species. It was found that Lewis basicity of these oxynitride materials increased by the pyrrole adsorption. Furthmore, the basic catalytic properties of nitrogen-incorporated zeolites were evaluated by Knoevenagal condensation of benzaldehyde with diethyl malonate and enhanced yield of product was achieved.

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Facile synthesis of high-surface area mesoporous biochar for energy storage via in-situ template strategy

Materials Letters ◽

10.1016/j.matlet.2018.07.106 ◽

2018 ◽

Vol 230 ◽

pp. 183-186 ◽

Cited By ~ 10

Author(s):

Yuan Gao ◽

Yulin Zhang ◽

Aimin Li ◽

Lei Zhang

Keyword(s):

Energy Storage ◽

Surface Area ◽

High Surface ◽

High Surface Area ◽

Facile Synthesis ◽

Mesoporous Biochar

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Electrochemically scrambled nanocrystals are catalytically active for CO2-to-multicarbons

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1918602117 ◽

2020 ◽

Vol 117 (17) ◽

pp. 9194-9201 ◽

Cited By ~ 9

Author(s):

Yifan Li ◽

Dohyung Kim ◽

Sheena Louisia ◽

Chenlu Xie ◽

Qiao Kong ◽

...

Keyword(s):

Structural Characteristics ◽

High Surface ◽

High Surface Area ◽

High Mobility ◽

Ex Situ ◽

Intrinsic Activity ◽

Air Exposure ◽

Disordered Structures ◽

Catalytically Active

Promotion of C–C bonds is one of the key fundamental questions in the field of CO2 electroreduction. Much progress has occurred in developing bulk-derived Cu-based electrodes for CO2-to-multicarbons (CO2-to-C2+), especially in the widely studied class of high-surface-area “oxide-derived” copper. However, fundamental understanding into the structural characteristics responsible for efficient C–C formation is restricted by the intrinsic activity of these catalysts often being comparable to polycrystalline copper foil. By closely probing a Cu nanoparticle (NP) ensemble catalyst active for CO2-to-C2+, we show that bias-induced rapid fusion or “electrochemical scrambling” of Cu NPs creates disordered structures intrinsically active for low overpotential C2+ formation, exhibiting around sevenfold enhancement in C2+ turnover over crystalline Cu. Integrating ex situ, passivated ex situ, and in situ analyses reveals that the scrambled state exhibits several structural signatures: a distinct transition to single-crystal Cu2O cubes upon air exposure, low crystallinity upon passivation, and high mobility under bias. These findings suggest that disordered copper structures facilitate C–C bond formation from CO2 and that electrochemical nanocrystal scrambling is an avenue toward creating such catalysts.

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In Situ and Ex Situ Microscopic Study of Propylene Polymerization With Heterogeneous Mgcl2-Supported Ziegler-Natta Catalysts

Microscopy and Microanalysis ◽

10.1017/s1431927600032657 ◽

2000 ◽

Vol 6 (S2) ◽

pp. 33-34

Author(s):

V. Oleshko ◽

P. Crozier ◽

R. Cantrell ◽

A. Westwood

Keyword(s):

Large Scale ◽

Heterogeneous Catalysts ◽

High Surface ◽

Light And Electron Microscopy ◽

High Surface Area ◽

Propylene Polymerization ◽

Ex Situ ◽

Co Catalysts ◽

Ziegler Natta Catalysts

The large-scale commercial production of polyolefins by catalytic Ziegler-Natta polymerization have stimulated the development of the third, fourth and fifth generation heterogeneous catalysts comprising high surface area defective MgCl2 with TiCl4, electron donors, and AlR3-co-catalysts. In spite of intensive research over the years, the present level of understanding of the catalysts is still incomplete because of their complex composition leading to a multitude of local active site environments. The aim of this work is to provide a new insight into the process via in situ video microscopy of gas phase propylene polymerization over MgCl2-supported Ziegler-Natta catalysts combined with ex situ characterization by light and electron microscopy techniques (SEM, TEM, HRTEM, STEM, PEELS and windowless EDX). Procedures for catalyst synthesis are described elsewhere. The catalysts were stored in a dry box under a He atmosphere (<lppm H2O/O2). Samples were transferred to specimen holders in the dry box and then transferred into the microscopes under high purge N2 conditions to prevent poisoning of the catalysts by air and moisture.

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