CuO/CexSn1−xO2 catalysts with low tin content for CO removal from H2-rich streams

• Doping ceria with low amount of tin enhanced low temperature reducibility.
• The presence of tin prevented the growth of doped-ceria crystal grains.
• 2.5–5 at.% of tin in the support enhanced the activity in CO-PROX reaction.
• The presence of tin in the support is detrimental for WGS reaction.
• Addition of low amount of oxygen to WGS improved the activity.

CuO/CexSn1−xO2 catalysts with low tin content (X ≥ 0.95) were synthesized and their activity was screened in CO-PROX, WGS and OWGS (Oxygen-enhanced WGS) reactions for CO removal from hydrogen rich streams. The samples were deeply characterized to evaluate their textural, structural and redox properties, as well as the surface composition and oxidation state of the elements. The activity of the catalysts in the three reactions was correlated to those physico–chemical properties. It is found that the addition of very low amount of tin (up to Sn/Ce atom ratio of 0.0525) increases both the OSC and the reducibility at low temperatures and is beneficial for CO-PROX as well as for OWGS reactions, while was detrimental for WGS reaction.