TY - JOUR
T1 - The catalytic activity of Ce-Hf, Ce-Hf-Mg mixed oxides and RuO2/HfO2 deposited on CeO2
T2 - Role of superoxide/peroxide in soot oxidation reaction
AU - Uppara, Hari Prasad
AU - Singh, Sunit Kumar
AU - Labhsetwar, Nitin Kumar
AU - Murari, Mudiyaru Subrahmanya
AU - Dasari, Harshini
N1 - Funding Information:
This work is supported by the Department of Science and Technology — Science and Engineering Research Council, India (DST SERB: EMR/2016/002598). The authors would like to acknowledge MRC, MNITJ for conducting Raman, TEM, and XPS analysis.
Publisher Copyright:
© 2021, The Korean Institute of Chemical Engineers.
PY - 2021/7
Y1 - 2021/7
N2 - The synthesis of binary mixed oxide Ce-Hf (CH), ternary mixed oxide Ce-Hf-Ru (CHR), and Ce-Hf-Mg (CHM) has been attempted using the PVP-assisted sol-gel method. The structural and surface morphology of the prepared catalysts were investigated and studied for the generation of superoxides (O22−)/peroxides (O22−) species and availability of lattice oxygen (O−) during soot oxidation reactions. The successfully incorporated Hf4+/Mg2+ into ceria (CH, CHM) enhances the redox potential sites on nano-flake morphology, thus produces more oxygen vacancies (□). However, Ru4+/Hf4+ was not doped into the ceria structure in CHR catalyst; it showed lesser structural distortions generating fewer oxygen vacancies. In addition, it was observed that better performing catalysts should possess lower oxidation temperature and be catalytically stable. Indeed, the ternary oxide CHR featured excellent catalytic properties when compared with the others. However, CHM was found structurally and catalytically stable with self-regenerative capability even after the repeated soot oxidation experiments. Thus, the possible soot oxidation mechanism has been proposed on the prepared catalysts.
AB - The synthesis of binary mixed oxide Ce-Hf (CH), ternary mixed oxide Ce-Hf-Ru (CHR), and Ce-Hf-Mg (CHM) has been attempted using the PVP-assisted sol-gel method. The structural and surface morphology of the prepared catalysts were investigated and studied for the generation of superoxides (O22−)/peroxides (O22−) species and availability of lattice oxygen (O−) during soot oxidation reactions. The successfully incorporated Hf4+/Mg2+ into ceria (CH, CHM) enhances the redox potential sites on nano-flake morphology, thus produces more oxygen vacancies (□). However, Ru4+/Hf4+ was not doped into the ceria structure in CHR catalyst; it showed lesser structural distortions generating fewer oxygen vacancies. In addition, it was observed that better performing catalysts should possess lower oxidation temperature and be catalytically stable. Indeed, the ternary oxide CHR featured excellent catalytic properties when compared with the others. However, CHM was found structurally and catalytically stable with self-regenerative capability even after the repeated soot oxidation experiments. Thus, the possible soot oxidation mechanism has been proposed on the prepared catalysts.
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U2 - 10.1007/s11814-021-0805-5
DO - 10.1007/s11814-021-0805-5
M3 - Article
AN - SCOPUS:85107906707
SN - 0256-1115
VL - 38
SP - 1403
EP - 1415
JO - Korean Journal of Chemical Engineering
JF - Korean Journal of Chemical Engineering
IS - 7
ER -