高稳定的Ni-B/蜂结构Al2O3催化剂用于甲干改造
Yuhao Luo1, Tongming Su1, Liuyun Chen1
1School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning, 530004, P. R. China.
Chemistry, an Asian journal
|July 29, 2024
概括
在蜂巢上用改性催化剂显示了对甲干改的增强稳定性. 这种两组分催化剂有效地抑制了烧结,并提高了焦炭耐受性,在长时间内保持高的转化率.
科学领域:
- 催化剂是一种催化剂.
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
背景情况:
- 双组分催化剂对于抑制 (Ni) 烧结至关重要.
- 甲干改造 (DRM) 是转化温室气体的一个重要过程.
研究的目的:
- 准备和评估蜂结构的Al2O3支持的Ni和B催化剂,以提高DRM中的焦炭耐受性.
- 研究 (B) 对Ni烧结和催化剂稳定性的影响.
主要方法:
- 合成具有蜂结构的支持Al2O3的Ni和Ni-B催化剂.
- 使用传输电子显微镜 (TEM) 进行表征.
- 超过100小时的DRM的催化性能测试.
- 在现场扩散反射红外里埃变换光谱 (in situ DRIFT) 用于机械学研究.
- 使用兰木尔-欣舍尔伍德-霍根-沃森 (LHHW) 模型进行动力建模.
主要成果:
- TEM证实,B添加显著减少了Ni粒子大小,从7.6nm降至4.2nm,抑制了烧结.
- -0.16B/Al2O3催化剂保持了高的CH4和CO2转化率 (约. 81.6%和87.2%) 超过100小时,与Ni/Al2O3不同,它显示了~5%的下降.
- 在现场的DRIFT光谱显示了Ni-0.16B/Al2O3上增强的CO2激活,有助于提高稳定性.
- LHHW模型准确地描述了R2值>0.9的内在动力学,并确定了激活能量.
结论:
- 蜂结构的Ni-0.16B/Al2O3催化剂在DRM中表现出卓越的稳定性和焦炭耐受性.
- 有效地抑制了Ni烧结,降低了颗粒大小,并增强了CO2激活,从而产生了优越的催化性能.
相关概念视频
02:50Catalysis
26.8K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
26.8K
02:13Reduction of Alkenes: Catalytic Hydrogenation
11.9K
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
11.9K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
7.7K
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
7.7K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.3K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.3K
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
17.9K
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
17.9K
01:28Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation
4.5K
Unlike the easy catalytic hydrogenation of an alkene double bond, hydrogenation of a benzene double bond under similar reaction conditions does not take place easily. For example, in the reduction of stilbene, the benzene ring remains unaffected while the alkene bond gets reduced. Hydrogenation of an alkene double bond is exothermic and a favorable process. In contrast, to hydrogenate the first unsaturated bond of benzene, an energy input is needed; that is, the process is endothermic. This is...
4.5K