Effects of preparation conditions of Ni/TiO2 catalysts for selective CO methanation in the reformate gas

Selective CO methanation in the reformate gas over Ni/TiO2 catalyst was carried out. Nickel metal salts (nitrate, sulfate, acetate, chloride and formate) used as a precursor of nickel, calcination temperatures (400–700 °C), reduction temperatures (350–650 °C) and nickel contents (1–30 wt%) affected to the CO methanation activity and CO/CO2 selectivity over the obtained Ni/TiO2 catalysts. The appropriate nickel precursors were nitrate and acetate and suitable calcination and reduction temperatures were 400–500 °C and 450–550 °C, respectively. An increase of nickel contents in the Ni/TiO2 catalysts improved to the CO methanation activity. Reverse water gas shift reaction activity was extremely low regardless of nickel contents. As a result, temperature window of Ni/TiO2 catalyst was constant and it could be shifted to desired position by changing nickel content.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (175 K)Download as PowerPoint slideHighlights► Catalytic performance of Ni/TiO2 was affected by preparation conditions. ► Increasing nickel contents promotes CO methanation at low temperature range. ► Increasing nickel contents declined CO/CO2 selectivity at high temperature range. ► Temperature window for selective CO methanation can be controlled by nickel contents.