INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 1 Politecnico di Milano Dipartimento di Energia Research activity from Nov 08 to May 09 at Laboratory of Catalyis and Catalytic Processes Gianpiero Groppi

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 2 Outline Development of new catalysts formulations –Pd only catalysts: effect of the support –Pt-Pd catalysts: Effect of Pt/Pd ratio Ecocat reference catalyst –Tests on washcoat powders –Monolith sample –S-poisoning

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 3 Outline Pd only catalysts: effect of the support Pt-Pd catalysts: Effect of Pt/Pd ratio Ecocat reference catalyst –Tests on washcoat powders –Monolith sample –S-poisoning

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 4 Effect of the support: preparation and characterization  Al 2 O 3 and ZrO 2 : T c = 950°C for 10 h  Ce and La added as nitrate, then calcined (Tc = 950°C for 10 h)  dry impregnation with Pd(NO 3 ) 2 solution, T c = 600°C for 10 h Pd load % (w/w) Support BET : SSA [m 2 /g] V p [cm 3 /g] XRD H 2 Chem. D %d p [nm] 2 Al 2 O 3 SASOL PURALOX SBA θ ( γ traces) % w/w CeO 2 – Al 2 O θ ( γ traces) CeO % w/w La 2 O 3 – Al 2 O θ ( γ traces) ZrO 2 MELCAT – Chemicals F20 936/ Monocline525

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 5 Test on powder catalysts: apparatus and procedures LEAN COMBUSTION : CH 4 0.5%; O 2 4%; H 2 O 1%; He/Ar; 93.5%; (30 min). REDUCING PULSE: CH 4 0.5%; H 2 O 1% ;He/Ar 97.5%; (120 s) PURGE: He 95%, 5%N 2 ( 30s ) T: 350°C, GHSV = Ncm 3 /g cat /h, P = 1 atm. quartz wool Powder catalyst thermocouple internal gas in Gas out Micro- reactor

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 6 Conditioning by redox cycles 2% Pd/Al 2 O 3 2% Pd/CeO 2 - Al 2 O 3 2% Pd/La 2 O 3 - Al 2 O 3 2% Pd/ZrO 2

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 7 Lean combustion behaviour after conditioning 2% Pd/Al 2 O 3 2% Pd/CeO 2 - Al 2 O 3 2% Pd/La 2 O 3 - Al 2 O 3 2% Pd/ZrO 2

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 8 TOF before and after conditioning Isothermal PFR  T = 350°C  P CH4 = 0.5 kPa  P H2O = 1.1 kPa  r = k. P CH4. P H2O -1 Support As prepared TOF [s -1 ] Conditioned TOF [s -1 ] K C /K AP Al 2 O ZrO CeO 2 – Al 2 O La 2 O 3 – Al 2 O

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 9 Outline Pd only catalysts: effect of the support Pt-Pd catalysts: Effect of Pt/Pd ratio Ecocat reference catalyst –Tests on washcoat powders –Monolith sample –S-poisoning

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 10 Characterization of bimetallic Pt-Pd systems nominal Pt/Pd Atomic ratio Actual Pd e Pt Load (% w/w) (AAS) actual Pt/Pd Atomic ratio d p XRD as prepared (nm) Pd dispersion (H 2 Chemisorption) 0 Pt: PdO: 5 21% Pd: 2.14Pt: n.d Pt: PdO: 8 13% Pd: 2.50Pt: n.d Pt: PdO: 7 12% Pd: 2.50Pt: n.d. 1 Pt: PdO: 6 15% Pd: 1.95Pt: 19 Constant nominal Pd load: 2% w/w

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 11 Activity of fresh catalysts

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 12 Conditioning by redox cycles

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 13 Pt-Pd catalysts: Reactivation behaviour

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 14 Pt-Pd catalysts: TPO measurements

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 15 Outline Pd only catalysts: effect of the support Pt-Pd catalysts: Effect of Pt/Pd ratio Ecocat reference catalyst –Tests on washcoat powders –Monolith sample –S-poisoning

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 16 Tests on washcoat powders Kc cond /Kc as received =2

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 17 Tests on washcoat powders: S poisoning T=400°C; WHSV=1.8E+5 Ncm 3 /g/h CH 4 =6000 ppm; SO 2 =15 ppm; O 2 =5.2%; H 2 O=3.5%; N 2 to balance

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain cm 15.2 cm 1.63 cm 2.5 cm Test on monolith samples: Experimental apparatus 6x6 channels

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 19 Test on monolith samples: preliminary results Conversion Q = 1215 Ncm 3 /min GHSV = h -1 (monolith volume) Temperature profiles Feed: 3% O 2 ; 0.7% CH 4 ; 0% H 2 O N 2 to balance

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 20 Powder 0.06 g  WHSV=1.5E+5 Ncm 3 /g/h Ground monolith g*  WHSW=1.0 E+6 Ncm 3 /g/h Monolith g*  WHSW=5.0 E+5 Ncm 3 /g/h *hp: 15% w/w washcoat Test on monolith samples: preliminary analysis kJ moles/atm/s.atm -1

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 21 Annular Reactor Laminar flow  negligible pressure drops High GHSV  10 6 – 10 7 Nl/Kg cat /h  distance from thermodynamic constraints Catalyst layer thickness 10 – 20  m Small annular gap 0.5 mm Regular structured geometry Efficient heat dissipation by radiation Thermal equilibrium across the section of the ceramic tube INLET OUTLET TC

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 22 Conclusions - 1 Marked activation of Pd-only catalysts upon reduction/re-oxidation cycles Limited effect of the support on the overall catalytic activity of Pd-only catalyst –Control of Pd dispersion (Al 2 O 3 >ZrO 2 ) –Slight decrease of TOF on increasing dispersion Addition of Pt is beneficial on the activity of the as prepared catalysts but depresses reactivation upon reduction/re-oxidation cycles On increasing Pt/Pd ratio oxidation of Pd is progressively inhibited (alloying or decoration/passivation)

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 23 Conclusions-2 On Ecocat reference sample redox cycles provides limited enhancement of activity Ecocat reference sample (washcoat powders) shows a similar activity to Al 2 O 3 supported Pd catalysts –Higher Pd load, lower dispersion? Treatment in SO 2 containing, lean combustion atmosphere results in marked catalyst deactivation (about 1/10 at 15 mg S /g wash ) Preliminary tests on monolith samples show comparable activity with powder catalysts. Significant temperature gradients are observed along the catalyst bed which might bias kinetic investigation.

INGAS 6 month meeting, Prague, May 2009 INGAS INtegrated GAS Powertrain 24 Future activities Kinetic studies on Ecocat reference catalyst (what reactor?) Testing of materials under project boundary conditions Studies on S-poisoning and regeneration treatments Studies on hydrothermal stability Further characterization studies, particularly of bimetallic system (to be discussed with ICSC-PAS)