Temporal analysis of products (TAP) reactor study of the dynamics of CO2 interaction with a Ru/γ-Al2O3 supported catalyst

Temporal Analysis of Products (TAP) Reactor Study of the Dynamics of CO2 Interaction with a Ru/g-Al2O3 Supported Catalyst II: Interaction Strength, Formation of Intermediates and Oxygen Exchange

“…The interaction of CO2 and its co-reactant H2 as well as of the reaction products H2O and CH4 with Ru/Al2O3 under CO2 methanation conditions, specifically at temperatures where CO formation can be excluded, is topic of the present paper. Expanding on our previous work [25],…”

“…For the multipulse experiments we first oxidized the Ru/Al2O3 catalyst in an O2/N2 gas mixture (1:1, 150 °C, 30 min, O150) and reduced it subsequently by exposing it to a sequence of CO/Ar pulses at 190 °C (for details see ref. [25]). Subsequently, we determined the dynamic activity for CO2 methanation by exposing the catalyst to a sequence of CO2/H2/Ar (4:1:1) pulses at 190 °C.…”

“…More important, these breaks may also lead to a sudden change in the incoming and thus also effluent pulse size, (see ref. [25]), which could be quantified and corrected for via the pulse size of the Ar standard.…”

“…After oxidation at 150 °C (O150, see Experimental) and subsequent reduction by a sequence of CO/Ar pulses at 190 °C [25], the catalyst was exposed to a sequence of 600 pulses CO2/H2/Ar at 190 °C, consisting of three subsequences of 200 pulses each (see Experimental).…”

“…As part of a comprehensive study of the reduction of COx over oxide supported Ru catalysts [9,[23][24] we had recently explored the interaction of CO2 with a Ru/-Al2O3 catalyst by temporal analysis of products (TAP) reactor measurements, focusing on the removal and deposition of active oxygen (Oact) from/on this catalyst (ref. [25] and references therein). In that study, we could demonstrate that exposing the catalyst to a multipulse sequence of CO at 190 °C can completely reduce the RuO2 nanoparticles (NPs) by removal of active oxygen (Oact) species.…”