The deactivation mechanism of Pb on the Ce/TiO2catalyst for the selective catalytic reduction of NOx with NH3: TPD and DRIFT studies.
It was well recognized that Pb had a poisoning effect on a SCR catalyst. In this study, the deactivation mechanism of Pb on the Ce/TiO2catalyst was investigated based on the characterization results of TPD and in situ DRIFT studies. It was found that the addition of Pb on the Ce/TiO2catalyst not only inhibited the adsorption and activation of NH3species, but also led to the decrease of the activity of adsorbed NH3species in the SCR reaction. The adsorption of NOx species and the oxidation of NO by O2over the Ce/TiO2catalyst were also suppressed by the addition of Pb, while the reactivity of adsorbed NO2species did not decrease. Moreover, the results revealed that the NH3-SCR reaction over the Ce/TiO2catalyst followed both the E-R and L-H mechanisms, while the NH3-SCR reaction over Ce/TiO2-Pb was mainly controlled by the L-H mechanism. The contributions of the L-H mechanism to the SCR reactions over Ce/TiO2and Ce/TiO2-Pb decreased with increasing reaction temperature. The deactivation of Ce/TiO2-Pb was mainly attributed to the suppressed NH3adsorption and activation, accompanied by the inhibited NO oxidation and the decrease of Brønsted acid sites.
School of Energy Source and Mechanical Engineering, Shanghai University of Electric Power, Shanghai, P. R. China. grta@zju.edu.cn and Shanghai Engineering Research Center of Power Generation Environment Protection, Shanghai, P. R. China.
Shu-Xian
SX
Wang
School of Energy Source and Mechanical Engineering, Shanghai University of Electric Power, Shanghai, P. R. China. grta@zju.edu.cn and Shanghai Engineering Research Center of Power Generation Environment Protection, Shanghai, P. R. China.
Rui-Tang
http://orcid.org/0000-0002-5646-5099
RT
Guo
School of Energy Source and Mechanical Engineering, Shanghai University of Electric Power, Shanghai, P. R. China. grta@zju.edu.cn and Shanghai Engineering Research Center of Power Generation Environment Protection, Shanghai, P. R. China.
Wei-Guo
WG
Pan
School of Energy Source and Mechanical Engineering, Shanghai University of Electric Power, Shanghai, P. R. China. grta@zju.edu.cn and Shanghai Engineering Research Center of Power Generation Environment Protection, Shanghai, P. R. China.
Ming-Yuan
MY
Li
School of Energy Source and Mechanical Engineering, Shanghai University of Electric Power, Shanghai, P. R. China. grta@zju.edu.cn and Shanghai Engineering Research Center of Power Generation Environment Protection, Shanghai, P. R. China.
Peng
P
Sun
School of Energy Source and Mechanical Engineering, Shanghai University of Electric Power, Shanghai, P. R. China. grta@zju.edu.cn and Shanghai Engineering Research Center of Power Generation Environment Protection, Shanghai, P. R. China.
Shu-Ming
SM
Liu
School of Energy Source and Mechanical Engineering, Shanghai University of Electric Power, Shanghai, P. R. China. grta@zju.edu.cn and Shanghai Engineering Research Center of Power Generation Environment Protection, Shanghai, P. R. China.
Shuai-Wei
SW
Liu
School of Energy Source and Mechanical Engineering, Shanghai University of Electric Power, Shanghai, P. R. China. grta@zju.edu.cn and Shanghai Engineering Research Center of Power Generation Environment Protection, Shanghai, P. R. China.
Xiao
X
Sun
School of Energy Source and Mechanical Engineering, Shanghai University of Electric Power, Shanghai, P. R. China. grta@zju.edu.cn and Shanghai Engineering Research Center of Power Generation Environment Protection, Shanghai, P. R. China.
Jian
J
Liu