酸化脱水条件下におけるボロン窒素触媒の変換を検知する

Alyssa M Love¹, Brijith Thomas², Sarah E Specht¹

¹Department of Chemistry , University of Wisconsin - Madison , 1101 University Avenue , Madison , Wisconsin 53706 , United States.

Journal of the American Chemical Society

|December 12, 2018

まとめ

六角性酸塩と酸塩ナノチューブは,酸化脱水条件下で堅固なB ((OH) _xO_3-x酸化相を形成する. この発見は,これらの材料の活性触媒部位に関する以前の仮説を修正しています.

科学分野:

材料科学
キャタリシス
表面化学

背景:

六角性酸塩 (h-BN) と酸塩ナノチューブ (BNNT) は,アルカン酸化脱水化 (ODH) に対して高い選択性を示しています.
表面の酸素含有量はODH後に著しく増加しますが,酸素化された種は十分に理解されていません.
これまでの仮説では,活性な触媒部位として,水酸化BNのエッジが示唆されていた.

研究の目的:

プロパンの催化ODH後にh-BNとBNNTで形成された酸素化された種の分子構造を解明する.
BN触媒によるODH反応における活性部位に関する既存の理解を修正する.

主な方法:

先進的な核磁気共振 (NMR) スペクトロスコーピー
スキャン電子顕微鏡 (SEM)
柔らかいX線吸収光譜 (XAS)

主要な成果:

プリスティンBN材料はODH条件下で酸化し,水分解する.
安定したB ((OH) _{O_3-x相形態で,異なるヒドロキシルとブリッジング酸化基を持つ3座標のボールを特徴とする (x = 0-3).}
この強固な酸化相が主要な種として特定され,以前の仮定に異議を唱える.

結論:

ODHのためのh-BNとBNNT触媒の活性相は,B ((OH) _xO_3-x酸化物であり,水酸化した縁だけではありません.
この研究は,ODH反応におけるBNベースの触媒の分子レベルの理解を修正したものである.

さらに関連する動画

07:03

Low-energy Cathodoluminescence for OxyNitride Phosphors

Published on: November 15, 2016

11.1K

11:15

HKUST-1 as a Heterogeneous Catalyst for the Synthesis of Vanillin

Published on: July 23, 2016

10.7K

関連する概念動画

03:14

Oxidation Numbers

42.6K

In redox reactions, the transfer of electrons occurs between reacting species. Electron transfer is described by a hypothetical number called the oxidation number (or oxidation state). It represents the effective charge of an atom or element, which is assigned using a set of rules.

42.6K

01:33

Bacterial Transformation

59.9K

In 1928, bacteriologist Frederick Griffith worked on a vaccine for pneumonia, which is caused by Streptococcus pneumoniae bacteria. Griffith studied two pneumonia strains in mice: one pathogenic and one non-pathogenic. Only the pathogenic strain killed host mice.
Griffith made an unexpected discovery when he killed the pathogenic strain and mixed its remains with the live, non-pathogenic strain. Not only did the mixture kill host mice, but it also contained living pathogenic bacteria that...

59.9K

01:15

Pyruvate Oxidation

168.8K

After glycolysis, the charged pyruvate molecules enter the mitochondria via active transport and undergo three enzymatic reactions. These reactions ensure that pyruvate can enter the next metabolic pathway so that energy stored in the pyruvate molecules can be harnessed by the cells.
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...

168.8K

03:11

Oxidation-Reduction Reactions

75.7K

Oxidation–Reduction Reactions

75.7K

01:26

Transformers

1.8K

A device that transforms voltages from one value to another using induction is called a transformer. A transformer consists of two separate coils, or windings, wrapped around the same soft iron core. However, they are electrically insulated from each other.
The iron core has a substantial relative permeability. Therefore, the magnetic field lines generated due to the current in one winding are almost entirely confined within the core, such that the same magnetic flux permeates each turn of both...

1.8K

01:26

Transformation

1.1K

Microbial communities are dynamic environments where cell lysis releases free DNA into the surroundings. Other cells can take up this extracellular DNA through a process known as transformation.When a cell incorporates this foreign DNA into its genome, resulting in genetic modification, the process is known as transformation. Cells capable of this process are termed competent. Competence can be natural, as observed in certain bacteria and archaea, or artificially induced in the...