ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Promotional effect of nickel addition on soot oxidation activity of Ce_0.9Pr_0.1O₂ oxide catalysts

Kirti Rajvanshi, Sunaina S. Patil, Lakhanlal, Hari Prasad Dasari, M. B. Saidutta, and Harshini Dasari

Chemical Engineering Department, National Institute of Technology Karnataka, Mangalore, India

E-mail: energyhari@nitk.edu.in

Received: 13 March 2020  Accepted: 29 June 2020

Abstract:

The present study investigates the promotional effect of Ni addition on soot oxidation activity of Ce_0.9Pr_0.1O₂ oxide catalysts. A series of xNi-PDC (x= 0, 3, 5, 7, 10, 15, and 20 mol%) catalysts were synthesized by solution combustion synthesis method and characterized by XRD, Raman spectroscopy and TEM analysis. XRD and SAED patterns of the catalysts show cubic fluorite structure of ceria with an average crystallite size of 6–8 nm, and only 20Ni-PDC display NiO as a secondary phase. Raman spectra of xNi-PDC catalysts display an increase in oxygen vacancies. With a minimum addition of 10 mol% Ni to PDC, i.e., the 10Ni-PDC catalyst showed optimum soot oxidation activity (T₅₀ = 360 °C) than compared to PDC and other Ni-PDC catalysts. Lattice strain and oxygen vacancies played a key descriptor role in showing better soot oxidation activity of the 10Ni-PDC catalyst. From the soot oxidation kinetic studies, the activation energy obtained by Ozawa plots for the 10Ni-PDC catalyst is 137 kJ/mol.

Keywords: Praseodymium-doped ceria; Nickel doping; Soot oxidation activity; Activation energy; Ozawa plots

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01275-2

Chemical Papers 74 (12) 4581–4592 (2020)