scholarly journals Catalytic activity of manganese oxide type raney catalyst prepared by alkali treatment of metal silicide

2020 ◽  
Vol 128 (7) ◽  
pp. 424-426
Author(s):  
Masataka KINOSHITA ◽  
Teruhisa HONGO ◽  
Yoshio MATSUI ◽  
Atsushi YAMAZAKI
Keyword(s):  
Catalytic Activity ◽  
Manganese Oxide ◽  
Alkali Treatment ◽  
Metal Silicide

Low-valence or tetravalent cation doping of manganese oxide octahedral molecular sieve (K-OMS-2) materials for nitrogen oxide emission abatement

2019 ◽  
Vol 9 (15) ◽  
pp. 4108-4117 ◽  
Author(s):  
Xiaomin Wu ◽  
Xiaolong Yu ◽  
Ziyi Chen ◽  
Zhiwei Huang ◽  
Guohua Jing
Keyword(s):  
Catalytic Activity ◽  
Oxygen Vacancy ◽  
Manganese Oxide ◽  
Nitrogen Oxide ◽  
Molecular Sieve ◽  
Oxide Catalysts ◽  
Nitrogen Oxide Emission ◽  
Vacancy Defects ◽  
Cation Doping ◽  
Tetravalent Cation

Substitutionally doped oxide catalysts with abundant oxygen vacancy defects (OVDs) can effectively improve the catalytic activity efficiency.

Catalytic Activity of Manganese Oxide Anchored on to Alumina and Zirconia for the Synthesis of Dihydropyrimidinones: Role of Acidity, Crystal Phase and Morphology

2014 ◽  
Vol 3 (1) ◽  
pp. 88-102 ◽  
Author(s):  
Mahadevaiah Rekha ◽  
Hagalahalli Hareesh ◽  
Nagaraju Kathyayini ◽  
Narasimaiah Nagaraju
Keyword(s):  
Catalytic Activity ◽  
Manganese Oxide ◽  
Crystal Phase

scholarly journals Evolution of the pore and framework structure of NaY zeolite during alkali treatment and its effect on methanol oxidative carbonylation over a CuY catalyst

2020 ◽  
Vol 44 (11-12) ◽  
pp. 710-720
Author(s):  
Lifei Yan ◽  
Tingjun Fu ◽  
Jiajun Wang ◽  
Nilesh Narkhede ◽  
Zhong Li
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Dimethyl Carbonate ◽  
Alkali Treatment ◽  
Oxidative Carbonylation ◽  
Framework Structure ◽  
Y Zeolite ◽  
Cage Structure ◽  
X Ray

Alkali treatment is widely used on aluminosilicate zeolites with high Si/Al ratios in order to fabricate mesopores in the framework. However, for zeolites with low Si/Al ratios, the effect of alkali treatment on the pore and framework structure needed further study. In this work, Y zeolite is treated with NaOH solutions of different concentrations and is used as the support for Cu-based catalysts for oxidative carbonylation of methanol to dimethyl carbonate. The physicochemical properties of the supports and corresponding catalysts are characterized by N2 adsorption–desorption, X-ray diffraction, X-ray fluorescence, transmission electron microscopy, inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, and H2-temperature-programmed reduction analyses. The results show that no obvious mesopores are formed under alkali treatment, even at high NaOH concentration. However, amorphous species present in the micropores of Y zeolite are removed, which increases the micropore surface area as well as the crystallinity. Simultaneously, the cage structure is partially destroyed, which also leads to a slight increase of the pore volume and surface area. The altered micropore structure eventually increases the content and accessibility of the exchanged Cu species, which is beneficial to the catalytic activity. When the concentration of NaOH is 0.6 M, the space time yield of dimethyl carbonate for the corresponding catalyst was 151.4 mg g−1 h−1 which is 3.3-fold higher than that of the untreated-Y-zeolite-supported Cu catalyst. However, further increasing the alkali treatment strength can seriously destroy the basic aluminosilicate structure of the Y zeolite and decrease its intrinsic ion-exchange capacity. This results in the formation of agglomerated CuO on the catalyst surface, which was not conducive to catalytic activity.

Influence of structure on catalytic activity of nano - manganese oxide

2020 ◽  
Vol 171 ◽  
pp. 108681
Author(s):  
R. Puspalata ◽  
D. Mal ◽  
S. Amirthapandian ◽  
S. Rangarajan
Keyword(s):  
Catalytic Activity ◽  
Manganese Oxide

Nanostructured OMO type Manganese Oxide – as Novel Support for Palladium towards Electrooxidation of Methanol and Ethylene Glycol

2012 ◽  
Vol 15 (4) ◽  
pp. 249-254 ◽  
Author(s):  
Ramanujam Kannan ◽  
Kulandaivelu Karunakaran ◽  
Samuel Vasanthkumar
Keyword(s):  
Catalytic Activity ◽  
Ethylene Glycol ◽  
Manganese Oxide ◽  
Reduction Method ◽  
Pd Nanoparticles ◽  
Active Oxygen ◽  
Electrolytic Solution ◽  
X Ray ◽  
Supporting Material ◽  
Electrooxidation Of Methanol

Octahedral molecular sieve type manganese oxide (OMO) was synthesized by the ultra sonic assisted hydrothermal method, and was subsequently used as supportive material for palladium (Pd) metal towards the electrooxidation of methanol and ethylene glycol. The Pd nanoparticles were coated on the OMO by insitu reduction method. Low quantity of 5% Pd metal was used and the electrocatalytic activity was studied. The prepared OMO and the OMO/Pd nanocomposite were characterized by powder X–ray diffractogram (XRD), Scanning Electron Microscopy (SEM), Energy dispersive X–ray spectroscopy (EDS) and electrochemical methods. These studies demonstrated that the OMO can act as a good catalyst supporting material. The OMO helps to enhance the catalytic activity of Pd metal by supplying the active oxygen, which is extracted from the electrolytic solution. The electrooxidation of EG shows improved catalytic activity.

A Composite Formation Route to Well-Crystalline Manganese Oxide Nanocrystals: High Catalytic Activity of Manganate-Alumina Nanocomposites

2011 ◽  
Vol 21 (12) ◽  
pp. 2301-2310 ◽  
Author(s):  
Tae Woo Kim ◽  
Hana Yoo ◽  
In Young Kim ◽  
Hyung-Wook Ha ◽  
Ah Reum Han ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Manganese Oxide ◽  
High Catalytic Activity ◽  
Composite Formation

Highly active water oxidation on nanostructured biomimetic calcium manganese oxide catalysts

2016 ◽  
Vol 4 (17) ◽  
pp. 6585-6594 ◽  
Author(s):  
Feng Rong ◽  
Jiao Zhao ◽  
Zheng Chen ◽  
Yuxing Xu ◽  
Yaopeng Zhao ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Manganese Oxide ◽  
Oxidation State ◽  
Water Oxidation ◽  
Oxide Catalysts ◽  
Structural Distortion ◽  
Manganese Oxide Catalysts ◽  
Highly Active

Nanostructured biomimetic birnessite CaxMnOy oxides with an intermediate Mn oxidation state and proper structural distortion show improved catalytic activity for the WOR.

scholarly journals Sintesis Nanopartikel Mangan Oksida dengan Metode Sol Gel dan Uji Aktivitas Katalitik terhadap Degradasi Zat Warna Rhodamin B

2020 ◽  
Vol 21 (2) ◽  
pp. 190
Author(s):  
Sri Rahayu ◽  
Netti Herawati ◽  
Mohammad Wijaya
Keyword(s):  
Catalytic Activity ◽  
Ethylene Glycol ◽  
Manganese Oxide ◽  
Sol Gel ◽  
Degradation Process ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Manganese Oxide Nanoparticles ◽  
X Ray ◽  
Rhodamin B

Telah dilakukan penelitian tentang sintesis nanopartikel mangan oksida menggunakan prekursor KMnO4 dengan metode sol gel, dengan menambahkan aditif etilendiamin dan etilen glikol yang berperan sebagai agen penstabil, selanjutnya menguji aktivitas katalitik dari mangan oksida tersebut terhadap proses degradasi warna rhodamin B. Penelitian ini bertujuan untuk mengetahui pengaruh penambahan zat aditif terhadap ukuran dan bentuk nanopartikel yang dihasilkan serta kemampuannya sebagai katalis dalam proses degradasi zat warna rhodamin B. Nanopartikel yang diperoleh, dikarakterisasi menggunakan XRD (X-Ray Diffraction) dan SEM (Scanning Elektron Microscope) serta penentuan aktivitas katalitik dalam proses degradasi terhadap zat warna rhodamin B dengan spektrofotometer UV-Vis. Hasil penelitian menunjukkan sintesis nanopartikel menggunakan aditif etilendiamin lebih baik dibandingkan dengan aditif etilen glikol karena ukuran nanopartikel berkisar antara 5,66-33,38 dalam bentuk tetragonal. Morfologi nanopartikel mangan oksida terlihat berbentuk bulat yang seragam. Nanopartikel mangan oksida hasil sintesis mampu mempercepat proses degradasi warna rhodamin B dengan persentase degradasi mencapai 85,6%. Kata kunci: Nanopartikel, Mangan Oksida , Sol gel dan Rhodamin B ABSTRACT Research has been carried out on the synthesis of manganese oxide nanoparticles using KMnO4 precursors with the sol gel method, by adding ethylenediamine and ethylene glycol additives which act as stabilizing agents, then tested the catalytic activity of the manganese oxide on the degradation process of Rhodamine B. This study aims to determine the effect of adding substances additives on the size and shape of the nanoparticles were produced and their ability as catalysts in the degradation process of Rhodamin B. Nanoparticles were obtained, characterized using XRD (X-Ray Diffraction)and SEM (Scanning Elektron Microscope)and determination of catalytic activity in the degradation process of rhodamine B dyes with UV-Vis spectrophotometer. The results showed that the synthesis of nanoparticles using ethylenediamine additives was better than ethylene glycol additives because the size of the nanoparticles ranged from 5.66 to 33.38 in the tetragonal form. The morphology of manganese oxide nanoparticles looks uniform in shape. Manganese oxide nanoparticles can accelerate the degradation process of Rhodamin B with a percentage of degradation reaching 85.6%. Keywords: Nanoparticles, Manganese Oxide, Sol gel and Rhodamin B

Nanogold supported on manganese oxide doped alumina microspheres as a highly active and selective catalyst for CO oxidation in a H2-rich stream

2015 ◽  
Vol 51 (100) ◽  
pp. 17728-17731 ◽  
Author(s):  
Yu-Xin Miao ◽  
Wen-Cui Li ◽  
Qiang Sun ◽  
Lei Shi ◽  
Lei He ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Manganese Oxide ◽  
High Catalytic Activity ◽  
Selective Catalyst ◽  
Support Interaction ◽  
Highly Active

The exceptionally high catalytic activity for CO-PROX reaction is due to the Au–support interaction and the unique reducibility of the support.

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