Related Experiment Video
Updated: Jul 9, 2025
10:51
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
12.2K
Boosting N2 Conversion into NH3 over Ru Catalysts via Modulating the Ru-Promoter Interface
Kailin Su1, Dongya Huang1, Hongpeng Fang1
1National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou, Fujian 350002, China.
ACS Applied Materials & Interfaces
|November 28, 2023
Summary
Altering the loading sequence of barium (Ba) and ruthenium (Ru) species significantly boosts ammonia (NH3) synthesis. Prior loading of Ba on graphitic carbon (GC) enhances catalyst performance by optimizing the Ru-promoter interface for N2 activation.
Area of Science:
- Catalysis
- Materials Science
- Chemical Engineering
Background:
- Promoters are crucial for ruthenium (Ru)-based catalysts in ammonia (NH3) synthesis, particularly for nitrogen (N2) activation.
- The arrangement and type of promoters significantly influence the NH3 synthesis rate.
Purpose of the Study:
- To investigate the effect of altering the loading sequence of barium (Ba) and Ru species on graphitic carbon (GC) supports for NH3 synthesis.
- To enhance the NH3 synthesis rate by optimizing the Ru-promoter interface through a simple loading sequence modification.
Main Methods:
- Synthesized Ba-Ru/GC and Ru-Ba/GC catalysts by varying the loading sequence of Ba and Ru species onto a graphitic carbon support.
- Evaluated catalyst performance via NH3 synthesis rate measurements at 400 °C and 1 MPa.
- Utilized characterization techniques to analyze the catalyst structure, dispersion, and electronic properties.
Main Results:
- The Ba-Ru/GC catalyst, with prior Ba loading, achieved an NH3 synthesis rate of 18.7 mmol gcat−1 h−1.
- This rate is 2.5 times higher than that of the Ru-Ba/GC catalyst prepared by conventional Ru-first loading.
- Prior Ba loading led to high dispersion of Ba, stabilization of small Ru particles, and enhanced electron donation from Ba to Ru.
Conclusions:
- The loading sequence of promoters critically impacts the Ru-promoter interface and catalytic activity in NH3 synthesis.
- Prior loading of Ba onto GC effectively disperses the promoter and stabilizes Ru, maximizing active sites for N2 activation.
- This strategy offers a simple yet effective approach to enhance NH3 synthesis performance by optimizing promoter utilization.
More Related Videos
Related Concept Videos
03:08Rate-Determining Steps
32.5K
Relating Reaction Mechanisms
In a multistep reaction mechanism, one of the elementary steps progresses significantly slower than the others. This slowest step is called the rate-limiting step (or rate-determining step). A reaction cannot proceed faster than its slowest step, and hence, the rate-determining step limits the overall reaction rate.
The concept of rate-determining step can be understood from the analogy of a 4-lane freeway with a short-stretch of traffic-bottleneck caused due to...
In a multistep reaction mechanism, one of the elementary steps progresses significantly slower than the others. This slowest step is called the rate-limiting step (or rate-determining step). A reaction cannot proceed faster than its slowest step, and hence, the rate-determining step limits the overall reaction rate.
The concept of rate-determining step can be understood from the analogy of a 4-lane freeway with a short-stretch of traffic-bottleneck caused due to...
32.5K
00:55Nitriles to Amines: LiAlH4 Reduction
3.5K
Nitriles are reduced to amines in the presence of strong reducing agents like lithium aluminum hydride through a typical nucleophilic acyl substitution. The reaction requires two equivalents of the reducing agent. The reducing agent acts as a source of hydride ions.
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
3.5K
01:13Preparation of Amines: Reduction of Amides and Nitriles
2.4K
Nitriles can be reduced to primary amines using reducing agents like lithium aluminum hydride or catalytic hydrogenation. The reduction introduces an amino group with an extra carbon in the skeleton. Nitriles are formed from the reaction between alkyl halides and sodium cyanide through the SN2 mechanism. Primary alkyl halides are the preferred substrates to prepare nitriles.
Amides can be reduced to primary, secondary, and tertiary amines using catalytic hydrogenation, active metals like Fe,...
Amides can be reduced to primary, secondary, and tertiary amines using catalytic hydrogenation, active metals like Fe,...
2.4K
01:12Preparation of Nitriles
2.1K
One of the common methods to prepare nitriles is the dehydration of amides. This method requires strong dehydrating agents like phosphorous pentoxide or boiling acetic anhydride for converting amides to nitriles. Another reagent namely, thionyl chloride also accomplishes the dehydration of amides, where amide acts as a nucleophile. The first step of the mechanism involves the nucleophilic attack by the amide on the thionyl chloride to form an intermediate. In the next step, the electron pairs...
2.1K
02:50Catalysis
27.0K
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.
27.0K
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