Related Experiment Video
Updated: Oct 4, 2025
05:50
Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments
Published on: May 11, 2017
11.0K
Optimized Design Method for Pt/SiO2-Al2O3 with High NH3-SCO Activity and Thermal Stability
Mengmeng Sun1, Shuo Zhou2, Suning Wang2
1College of Science, Sichuan Agricultural University, Xin Kang Road, Yucheng District, Ya'an 625014, China.
ACS Omega
|February 7, 2022
Summary
The strong electrostatic adsorption (SEA) method yields superior Pt/SiO2-Al2O3 catalysts with enhanced thermal stability and ammonia oxidation activity compared to traditional impregnation (IM). SEA catalysts maintain smaller Pt particle sizes, crucial for efficient catalytic performance.
Area of Science:
- Heterogeneous catalysis
- Materials science
- Surface chemistry
Background:
- Platinum (Pt) supported on silica-alumina (SiO2-Al2O3) is a key catalyst in various chemical reactions.
- Catalyst deactivation due to particle agglomeration under hydrothermal conditions is a significant challenge.
- Optimizing Pt dispersion and stability is crucial for enhancing catalytic efficiency.
Purpose of the Study:
- To compare the preparation methods of impregnation (IM) and strong electrostatic adsorption (SEA) for Pt/SiO2-Al2O3 catalysts.
- To systematically investigate the differences in Pt particle size, dispersion, and surface properties.
- To evaluate the ammonia oxidation activity and hydrothermal stability of the catalysts prepared by IM and SEA.
Main Methods:
- Preparation of Pt/SiO2-Al2O3 catalysts using traditional impregnation (IM) and strong electrostatic adsorption (SEA) methods.
- Characterization of fresh and hydrothermally aged catalysts to analyze Pt particle size, distribution, and adsorption sites.
- Evaluation of catalytic performance through ammonia oxidation activity measurements at different temperatures.
Main Results:
- SEA method resulted in selective Pt adsorption on Al2O3 with smaller average particle size (2.7 nm) compared to IM (6.6 nm).
- SEA catalysts exhibited significantly better hydrothermal stability, with minimal Pt agglomeration after aging (average size 3.2 nm).
- Pt/SiO2-Al2O3-SEA demonstrated higher ammonia oxidation activity, with lower temperatures for 50% conversion (216 °C fresh, 223 °C aged) than IM catalysts.
Conclusions:
- The strong electrostatic adsorption (SEA) method is superior for preparing thermally stable and highly active Pt/SiO2-Al2O3 catalysts.
- SEA effectively controls Pt particle size and prevents agglomeration, leading to improved catalytic performance in ammonia oxidation.
- SEA offers a promising approach for designing robust supported noble metal catalysts for demanding applications.
