Catalyst deactivation during steam reforming of acetic acid over Pt/ZrO₂

Steam reforming of acetic acid as a model compound present in bio-oil over Pt/ZrO₂ catalysts has been investigated. Pt/ZrO₂ yields steam reforming products (i.e., H₂, CO, CO₂) to the amounts predicted by thermodynamic equilibrium; however, conversion and yields dropped rapidly with time on course. The deactivation was due to blockage of active sites by coke/oligomer formed. This report clarifies cause of the deactivation during steam reforming of acetic acid. It was found that many products can be formed from acetic acid on ZrO₂, such as acetone. The experimental results confirmed that aldol condensation of acetone took place on ZrO₂ to give larger compounds which can easily become deposits to block active sites for steam reforming. In order to develop durable catalysts for steam reforming of bio-oil, support should be designed to enhance activation of water, minimize dehydration reactions and thus oligomer formation.