Pretreatment of Ru/TiO2 Catalysts Influences Activity and Selectivity in CO2 Hydrogenation

Abstract

The need for a pretreatment strategy for CO and CO2 hydrogenation is already known for Fe- and Co-based Fischer-Tropsch catalysts but is unexplored for Ru-based catalysts. The aim of this work was to establish a starting point from which to systematically develop pretreatment strategies to maximize the activity, selectivity, and stability of the catalyst. The results show that all pretreatment strategies tested here are equal or better than no pretreatment for the conversion of CO2. The pretreatment with CO/H2 synthesis gas can double the activity, but the advantage is diminished over 80 h of experiment. In contrast, the use of dilute O2 significantly increases the selectivity towards methane while pure CO2 significantly increases the selectivity to higher hydrocarbons.