scholarly journals Synergistic Effects of Bimetallic AuPd and La2O3 in the Catalytic Reduction of NO with CO

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 916
Author(s):  
Xianwei Wang ◽  
Nobutaka Maeda ◽  
Daniel M. Meier

Bimetallic AuPd nanoparticles supported on TiO2 are known to catalyze the reduction of NO with CO. Here, we investigated the effects of the addition of lanthanum oxide to a AuPd/TiO2 catalyst with a AuPd particle size of 2.1–2.2 nm. The addition of La2O3 enhanced the catalytic activity; for example, at 250 °C, there was 40.9% NO conversion and 49.3% N2-selectivity for AuPd/TiO2, and 100% NO conversion and 100% N2-selectivity for AuPd-La (1:1)/TiO2. The temperature requiring 100% NO conversion dropped from 400 °C to 200 °C by the simple post-impregnation of La2O3 onto AuPd/TiO2. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) combined with modulation excitation spectroscopy (MES) demonstrated that CO adsorption occurs first on Au atoms and then, within 80 s, moves onto Pd atoms. This transformation between two adsorption sites was facilitated by the addition of La2O3.

1992 ◽  
Vol 46 (8) ◽  
pp. 1279-1287 ◽  
Author(s):  
J. Y. Shen ◽  
A. Sayari ◽  
S. Kaliaguine

In situ diffuse reflectance infrared spectroscopy of CO adsorption on reduced Ru/ZSM-5 reveals that, under appropriate conditions, in addition to the linearly adsorbed CO on metallic Ru particles (at 2045 ± 10 cm−1), two multicarbonyls involving oxidized Ru can be generated. These multicarbonyl species are characterized by IR doublets at 2080 and 2138 cm−1 and at 2086 and 2150 cm−1, respectively. Direct evidence for the consumption of both types of the ZSM-5 surface hydroxyl groups (silanol and Brønsted) during the oxidative adsorption of CO has been obtained. Each of these two OH types is believed to be associated with one of the multicarbonyl species.


2019 ◽  
Vol 9 (3) ◽  
pp. 718-730 ◽  
Author(s):  
Jian-Wen Shi ◽  
Yao Wang ◽  
Ruibin Duan ◽  
Chen Gao ◽  
Baorui Wang ◽  
...  

Non-manganese-based metal oxides are promising catalysts for the NH3-SCR (selective catalytic reduction) of NOx at low temperatures.


2014 ◽  
Vol 535 ◽  
pp. 709-712
Author(s):  
Ye Jiang ◽  
Yan Yan ◽  
Shan Bo Huang ◽  
Xiong Zhang ◽  
Xin Wei Wang ◽  
...  

A Ce-Zr-Ti oxide catalyst was prepared by an impregnation method and tested for the selective catalytic reduction of NO with NH3. The Ce-Zr-Ti oxide catalyst exhibited high activity and more than 95% NO conversion was obtained within the temperature range 300-500 °C at the high gas hourly space velocity of 50,000 h-1. The addition of Zr improved the activity of Ce-Ti oxides especially at higher reaction temperatures and their resistance to SO2.


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