Highly active and coke resistant Ni/CeZrO2 catalyst prepared by cold plasma decomposition for CO2 reforming of methane

The ceria-zirconia solid solution is an excellent support of nickel catalysts for CO2 reforming of methane. In this work, we further improve the activity of the ceria-zirconia solid solution supported Ni catalyst via decomposition of nickel precursor by dielectric barrier discharge (DBD) plasma at ca.150 °C, followed by hydrogen reduction at 500 °C in the absence of DBD plasma. Compared to the catalyst prepared by the conventional thermal decomposition, the plasma decomposed catalyst possesses smaller Ni nanoparticles with mainly exposed Ni(111) lattice fringe. The plasma decomposed catalyst shows higher reducibility, which helps to form more active Ni0 species after hydrogen reduction. It also exhibits more basic sites and oxygen vacancies, promoting the activation of CO2. Additionally, the plasma decomposed catalyst tends to form highly reactive carbon, from methane decomposition, the initial reaction of CO2 reforming, towards the reaction with carbon dioxide. This leads to an enhanced coke resistance for CO2 reforming.