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WP2.2 Advanced Catalyst Development. I nstitute of Catalysis and Surface Chemistry Polish Academy of Sciences 18 months research activities. WP2.2 Advanced Catalyst Development Mixed Oxide Catalysts (ICSC PAS). Objective: Design of an active and stable catalyst for CH 4 combustion
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WP2.2 Advanced Catalyst Development Institute of Catalysis and Surface Chemistry Polish Academy of Sciences 18 months research activities
WP2.2 Advanced Catalyst DevelopmentMixed Oxide Catalysts (ICSC PAS) Objective: Design of an active and stable catalyst for CH4 combustion based on transition metal mixed oxides Scope of work: • synthesis • physico-chemical characterization • catalytic testing Innovative aspect: • novel precursors - hydrotalcites, pillared clays • new compositions/modified synthesis methods for known structures (spinels, perovskites, hexaaluminates) • synthesis in the presence of support suitable for washcoat preparation
WP2.2 Advanced Catalyst DevelopmentMixed oxide catalyst (ICSC PAS) Summary of catalyst synthesis and characterization work (over 80 catalyst formulations): • Spinels and perovskites derived from hydrotalcite-like precursors (metal elements: Cu, Mn, Co, Cr, Ce, Zr, Pd, La, Al, different stoichiometries) • Spinels and perovskites prepared by sol-gel procedure from citrate precursors (metal elements: Cu, Mn, Co, Al, Fe, La, Pd) • Hexaaluminates (metal elements: Mn, Mg,Al, La) • Pillared clays (metal elements: Zr, Al, Pd, clay: montmorillonite) Characterization methods: XRD, chemical analysis (ICP-OES), SEM, XPS, FT-IR, TG/DTG/DSC, TPR, N2 adsorption at 77 K
Spinels/Ht Spinels/Ht PILC 114 m2/g 239 m2/g 98 m2/g 215 m2/g 66 m2/g 101 m2/g 182 m2/g 86 m2/g 118 m2/g 200 m2/g 104 m2/g 94 m2/g 229 m2/g 98 m2/g 85 m2/g 55 m2/g 265 m2/g 30 m2/g 66 m2/g 280 m2/g 237 m2/g Spinels, Perovskites/Cit Hexaaluminates Perovskites/Cit, Ht 24 m2/g 3 m2/g 18 m2/g 19 m2/g 16 m2/g 197 m2/g 76 m2/g 2 m2/g 185 m2/g 324 m2/g 26 m2/g 257 m2/g 33 m2/g 229 m2/g 2 m2/g 17 m2/g 17 m2/g WP2.2 Advanced Catalyst Development • Different compositions • Ht – hydrotalcite-derived • Different structures • Cit – citrate-derived perovskite • PILC – pilllared clays • Different specific surfaces
33 m2/g 2 m2/g 151 m2/g 237 m2/g LaCo(1:1)Cit LaFe(1:1)Cit MnAl(2:1)Ht CuMn(2:1)Cit/Puralox 76 m2/g 18 m2/g 19 m2/g 182 m2/g MnAl(2:1)Cit CuMn(1:2)Cit MnLaAl(1:1:11)Ha Pd2-Zr-PILC WP2.2 Advanced Catalyst Development • Different morphologies
As received catalysts SV=10000 h-1 WP2.2 Advanced Catalyst DevelopmentMixed Oxide Catalysts – Catalytic Screening Catalytic testing – summary • over 120 catalytic tests, carried out at SV=10000 and 50000 h-1 on as received and thermally aged catalysts • hydrotalcite-derived mixed oxide catalysts belong tomost active catalysts • hexaaluminates form the least active group • selected citrate-derived mixed oxides and pillared clays also display appreciable activity • all tested mixed oxide catalysts are much less active than the reference noble metalECOCAT sample.
WP2.2 Advanced Catalyst Development Supporting on a Puralox carrier (γ-Al2O3+ 5% ZrO2 and 2% CeO2) • Beneficial influence of the support
WP2.2 Advanced Catalyst Development Thermal ageing tests – summary λ=1, SV=50000 h-1 5h 600oC, 10 h 800oC,
WP2.2 Advanced Catalyst Development Thermal ageing tests – most active catalysts Cu-Mn-based mixed oxides form most active group
WP2.2 Advanced Catalyst Development Thermal ageing tests λ=1, 5h 600oC, 10 h 800oC, SV=50000 h-1 Cu-Mn-based mixed oxide catalysts supported on Puralox (γ-Al2O3+ 5%ZrO2+ 2%CeO2) show good thermal stability
WP2.2 Advanced Catalyst DevelopmentMixed Oxide Catalysts – Conclusions and Outlook Conclusions • Best catalysts are based on CuMn mixed oxide systems and show activity exceeding that described in literature for mixed oxide systems. However, severe thermal treatment foreseen by InGas boundary conditions causes significant drop in catalytic performance of unsupported active phase. • Use of appropriate support improves thermal stability of mixed oxide active phase and renders the material ready for washcoat preparation. Addition of small amount of Pd at the stage of precursor synthesis is beneficial for the activity.
WP2.2 Advanced Catalyst DevelopmentMixed Oxide Catalysts – Conclusions and Outlook Outlook Optimization of selected formulations aimed at enhancement of activity, prevention of sintering and maximization of the specific surface areavia: • use of promoters (including noble metals) and carriers • synthesis modification (e.g. reverse microemulsions, ultrafine grinding) trageted especially at increase of dispersion of thermally stable low surface area oxidic phases (perovskites, hexaaluminates)
Ht – conventional synthesis Oil phase Surfactant Water (reaction medium) Ht – reverse microemulsion WP2.2 Advanced Catalyst DevelopmentMixed Oxide Catalysts – Conclusions and Outlook Reverse microemulsion limits particle size of precipitate