Manganese oxide as an alternative to vanadium-based catalysts for effective conversion of glucose to formic acid in water

2021 ◽  
Author(s):  
Jialu Li ◽  
Richard Lee Smith Jr. ◽  
Siyu Xu ◽  
De Li ◽  
Jirui Yang ◽  
...  
Keyword(s):  
Formic Acid ◽  
Manganese Oxide ◽  
Hydrothermal Conditions ◽  
Reaction Systems ◽  
Vanadium Based Catalysts

MnOx catalysts were synthesized under hydrothermal conditions for converting glucose to formic acid (FA) in water with the objective to develop vanadium-free reaction systems. An FA yield of 81.1% was...

scholarly journals A new form of NaMnAsO4

2019 ◽  
Vol 75 (7) ◽  
pp. 969-971
Author(s):  
Matthias Weil ◽  
Théo Veyer
Keyword(s):  
Crystal Structure ◽  
Manganese Oxide ◽  
Trigonal Bipyramid ◽  
Framework Structure ◽  
Hydrothermal Conditions ◽  
Coordination Numbers ◽  
Distorted Octahedral Coordination ◽  
Sodium Cations ◽  
Distorted Octahedral ◽  
New Form

A new form of NaMnAsO4, sodium manganese(II) orthoarsenate, has been obtained under hydrothermal conditions, and is referred to as the β-polymorph. In contrast to the previously reported orthorhombic α-polymorph that crystallizes in the olivine-type of structure and has one manganese(II) cation in a distorted octahedral coordination, the current β-polymorph contains two manganese(II) cations in [5]-coordination, intermediate between a square-pyramid and a trigonal bipyramid. In the crystal structure of β-NaMnAsO4, four [MnO5] polyhedra are linked through vertex- and edge-sharing into finite {Mn4O16} units strung into rows parallel to [100]. These units are linked through two distinct orthoarsenate groups into a framework structure with channels propagating parallel to the manganese oxide rows. Both unique sodium cations are situated inside the channels and exhibit coordination numbers of six and seven. β-NaMnAsO4 is isotypic with one form of NaCoPO4 and with NaCuAsO4.

Reduction of formic acid to methanol under hydrothermal conditions in the presence of Cu and Zn

2012 ◽  
Vol 114 ◽  
pp. 658-662 ◽  
Author(s):  
Jianke Liu ◽  
Xu Zeng ◽  
Min Cheng ◽  
Jun Yun ◽  
Qiuju Li ◽  
...  
Keyword(s):  
Formic Acid ◽  
Hydrothermal Conditions ◽  
Cu And Zn

Low-temperature and highly efficient conversion of saccharides into formic acid under hydrothermal conditions

AIChE Journal ◽  
2016 ◽  
Vol 62 (10) ◽  
pp. 3657-3663 ◽  
Author(s):  
Jun Yun ◽  
Guodong Yao ◽  
Fangming Jin ◽  
Heng Zhong ◽  
Atsushi Kishita ◽  
...  
Keyword(s):  
Low Temperature ◽  
Formic Acid ◽  
Hydrothermal Conditions ◽  
Efficient Conversion ◽  
Highly Efficient

Controllable synthesis, characterization, and electrochemical properties of manganese oxide nanoarchitectures

2008 ◽  
Vol 23 (3) ◽  
pp. 780-789 ◽  
Author(s):  
Lichun Zhang ◽  
Liping Kang ◽  
Hao Lv ◽  
Zhikui Su ◽  
Kenta Ooi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Properties ◽  
Manganese Oxide ◽  
Manganese Oxides ◽  
Hydrothermal Reaction ◽  
Reaction Times ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Hydrothermal Temperature ◽  
Transmission Electron

Flowerlike manganese oxide microspheres and cryptomelane-type manganese oxide nanobelts were selectively synthesized by a simple decomposition of KMnO4 under mild hydrothermal conditions without using template or cross-linking reagents. The effect of varying the hydrothermal times and temperatures on the nanostructure, morphology, compositional, and electrochemical properties of the obtained manganese oxides was investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) studies showed that the flowerlike manganese oxide microspheres could be obtained at relatively low hydrothermal temperatures, while high hydrothermal temperatures were favorable for the formation of cryptomelane-type manganese oxide nanobelts. A morphology and crystalline evolution of the nanostructures was observed as the hydrothermal temperature was increased from 180 to 240 °C. On the basis of changing the temperatures and hydrothermal reaction times, the formation mechanism of cryptomelane-type manganese oxide nanobelts is discussed. Cyclic voltammetry (CV) was used to evaluate the electrochemical properties of the obtained manganese oxide nanostructures, and the results show that the electrochemical properties depend on their shape and crystalline structure. This easily controllable, template-free, and environmentally friendly method has the potential for being used in syntheses of manganese oxide nanomaterials with uniform morphologies and crystal structures.

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