Controlled reaction depth by metal (M=Fe, Ni, Mn and Ti) doped ceria in selective oxidation of ethane with carbon dioxide

Abstract

Fe, Ni, Mn, and Ti were directly doped into CeO2 lattice by hydrothermal method to form solid solution catalysts. Various techniques including N2 adsorption/desorption, XRD, HRTEM, XPS, H2-TPR, CO2-TPD, O2-TPD, Raman, and thermogravimetric techniques were applied to study the structural evolution under the preparation/reaction conditions. The incorporation of metal elements distorted the lattice, the difference of interaction resulted in the differences of redox, oxygen activity, basicity and surface etc. properties. The catalytic conversion of ethane with CO2 exhibited dry reforming feature on Ni doped ceria because of the in situ formed metallic Ni0, and selective oxidation feature on Fe, Mn and Ti doped samples. The number and activity of lattice oxygen played the dominant role in affecting activity and selectivity. The solid solution catalysts revealed good coke resistance.